diff --git a/docs/app-dev/abci-spec.md b/docs/app-dev/abci-spec.md
deleted file mode 100644
index 6d0f712a2..000000000
--- a/docs/app-dev/abci-spec.md
+++ /dev/null
@@ -1,367 +0,0 @@
-# ABCI Specification
-
-### XXX
-
-DEPRECATED: Moved [here](../spec/abci/abci.md)
-
-## Message Types
-
-ABCI requests/responses are defined as simple Protobuf messages in [this
-schema file](https://github.com/tendermint/tendermint/blob/master/abci/types/types.proto).
-TendermintCore sends the requests, and the ABCI application sends the
-responses. Here, we provide an overview of the messages types and how
-they are used by Tendermint. Then we describe each request-response pair
-as a function with arguments and return values, and add some notes on
-usage.
-
-Some messages (`Echo, Info, InitChain, BeginBlock, EndBlock, Commit`),
-don't return errors because an error would indicate a critical failure
-in the application and there's nothing Tendermint can do. The problem
-should be addressed and both Tendermint and the application restarted.
-All other messages (`SetOption, Query, CheckTx, DeliverTx`) return an
-application-specific response `Code uint32`, where only `0` is reserved
-for `OK`.
-
-Some messages (`SetOption, Query, CheckTx, DeliverTx`) return
-non-deterministic data in the form of `Info` and `Log`. The `Log` is
-intended for the literal output from the application's logger, while the
-`Info` is any additional info that should be returned.
-
-The first time a new blockchain is started, Tendermint calls
-`InitChain`. From then on, the Block Execution Sequence that causes the
-committed state to be updated is as follows:
-
-`BeginBlock, [DeliverTx], EndBlock, Commit`
-
-where one `DeliverTx` is called for each transaction in the block.
-Cryptographic commitments to the results of DeliverTx, EndBlock, and
-Commit are included in the header of the next block.
-
-Tendermint opens three connections to the application to handle the
-different message types:
-
-- `Consensus Connection - InitChain, BeginBlock, DeliverTx, EndBlock, Commit`
-- `Mempool Connection - CheckTx`
-- `Info Connection - Info, SetOption, Query`
-
-The `Flush` message is used on every connection, and the `Echo` message
-is only used for debugging.
-
-Note that messages may be sent concurrently across all connections -a
-typical application will thus maintain a distinct state for each
-connection. They may be referred to as the `DeliverTx state`, the
-`CheckTx state`, and the `Commit state` respectively.
-
-See below for more details on the message types and how they are used.
-
-## Request/Response Messages
-
-### Echo
-
-- **Request**:
-  - `Message (string)`: A string to echo back
-- **Response**:
-  - `Message (string)`: The input string
-- **Usage**:
-  - Echo a string to test an abci client/server implementation
-
-### Flush
-
-- **Usage**:
-  - Signals that messages queued on the client should be flushed to
-    the server. It is called periodically by the client
-    implementation to ensure asynchronous requests are actually
-    sent, and is called immediately to make a synchronous request,
-    which returns when the Flush response comes back.
-
-### Info
-
-- **Request**:
-  - `Version (string)`: The Tendermint version
-- **Response**:
-  - `Data (string)`: Some arbitrary information
-  - `Version (Version)`: Version information
-  - `LastBlockHeight (int64)`: Latest block for which the app has
-    called Commit
-  - `LastBlockAppHash ([]byte)`: Latest result of Commit
-- **Usage**:
-  - Return information about the application state.
-  - Used to sync Tendermint with the application during a handshake
-    that happens on startup.
-  - Tendermint expects `LastBlockAppHash` and `LastBlockHeight` to
-    be updated during `Commit`, ensuring that `Commit` is never
-    called twice for the same block height.
-
-### SetOption
-
-- **Request**:
-  - `Key (string)`: Key to set
-  - `Value (string)`: Value to set for key
-- **Response**:
-  - `Code (uint32)`: Response code
-  - `Log (string)`: The output of the application's logger. May
-    be non-deterministic.
-  - `Info (string)`: Additional information. May
-    be non-deterministic.
-- **Usage**:
-  - Set non-consensus critical application specific options.
-  - e.g. Key="min-fee", Value="100fermion" could set the minimum fee
-    required for CheckTx (but not DeliverTx - that would be
-    consensus critical).
-
-### InitChain
-
-- **Request**:
-  - `Time (google.protobuf.Timestamp)`: Genesis time.
-  - `ChainID (string)`: ID of the blockchain.
-  - `ConsensusParams (ConsensusParams)`: Initial consensus-critical parameters.
-  - `Validators ([]ValidatorUpdate)`: Initial genesis validators.
-  - `AppStateBytes ([]byte)`: Serialized initial application state. Amino-encoded JSON bytes.
-- **Response**:
-  - `ConsensusParams (ConsensusParams)`: Initial
-    consensus-critical parameters.
-  - `Validators ([]ValidatorUpdate)`: Initial validator set (if non empty).
-- **Usage**:
-  - Called once upon genesis.
-  - If ResponseInitChain.Validators is empty, the initial validator set will be the RequestInitChain.Validators
-  - If ResponseInitChain.Validators is not empty, the initial validator set will be the
-    ResponseInitChain.Validators (regardless of what is in RequestInitChain.Validators).
-  - This allows the app to decide if it wants to accept the initial validator
-    set proposed by tendermint (ie. in the genesis file), or if it wants to use
-    a different one (perhaps computed based on some application specific
-    information in the genesis file).
-
-### Query
-
-- **Request**:
-  - `Data ([]byte)`: Raw query bytes. Can be used with or in lieu
-    of Path.
-  - `Path (string)`: Path of request, like an HTTP GET path. Can be
-    used with or in liue of Data.
-  - Apps MUST interpret '/store' as a query by key on the
-    underlying store. The key SHOULD be specified in the Data field.
-  - Apps SHOULD allow queries over specific types like
-    '/accounts/...' or '/votes/...'
-  - `Height (int64)`: The block height for which you want the query
-    (default=0 returns data for the latest committed block). Note
-    that this is the height of the block containing the
-    application's Merkle root hash, which represents the state as it
-    was after committing the block at Height-1
-  - `Prove (bool)`: Return Merkle proof with response if possible
-- **Response**:
-  - `Code (uint32)`: Response code.
-  - `Log (string)`: The output of the application's logger. May
-    be non-deterministic.
-  - `Info (string)`: Additional information. May
-    be non-deterministic.
-  - `Index (int64)`: The index of the key in the tree.
-  - `Key ([]byte)`: The key of the matching data.
-  - `Value ([]byte)`: The value of the matching data.
-  - `Proof ([]byte)`: Proof for the data, if requested.
-  - `Height (int64)`: The block height from which data was derived.
-    Note that this is the height of the block containing the
-    application's Merkle root hash, which represents the state as it
-    was after committing the block at Height-1
-- **Usage**:
-  - Query for data from the application at current or past height.
-  - Optionally return Merkle proof.
-
-### BeginBlock
-
-- **Request**:
-  - `Hash ([]byte)`: The block's hash. This can be derived from the
-    block header.
-  - `Header (struct{})`: The block header.
-  - `LastCommitInfo (LastCommitInfo)`: Info about the last commit, including the
-    round, and the list of validators and which ones signed the last block.
-  - `ByzantineValidators ([]Evidence)`: List of evidence of
-    validators that acted maliciously.
-- **Response**:
-  - `Tags ([]cmn.KVPair)`: Key-Value tags for filtering and indexing
-- **Usage**:
-  - Signals the beginning of a new block. Called prior to
-    any DeliverTxs.
-  - The header contains the height, timestamp, and more - it exactly matches the
-    Tendermint block header. We may seek to generalize this in the future.
-  - The `LastCommitInfo` and `ByzantineValidators` can be used to determine
-    rewards and punishments for the validators. NOTE validators here do not
-    include pubkeys.
-
-### CheckTx
-
-- **Request**:
-  - `Tx ([]byte)`: The request transaction bytes
-- **Response**:
-  - `Code (uint32)`: Response code
-  - `Data ([]byte)`: Result bytes, if any.
-  - `Log (string)`: The output of the application's logger. May
-    be non-deterministic.
-  - `Info (string)`: Additional information. May
-    be non-deterministic.
-  - `GasWanted (int64)`: Amount of gas request for transaction.
-  - `GasUsed (int64)`: Amount of gas consumed by transaction.
-  - `Tags ([]cmn.KVPair)`: Key-Value tags for filtering and indexing
-    transactions (eg. by account).
-- **Usage**: Validate a mempool transaction, prior to broadcasting
-  or proposing. CheckTx should perform stateful but light-weight
-  checks of the validity of the transaction (like checking signatures
-  and account balances), but need not execute in full (like running a
-  smart contract).
-
-  Tendermint runs CheckTx and DeliverTx concurrently with eachother,
-  though on distinct ABCI connections - the mempool connection and the
-  consensus connection, respectively.
-
-  The application should maintain a separate state to support CheckTx.
-  This state can be reset to the latest committed state during
-  `Commit`. Before calling Commit, Tendermint will lock and flush the mempool,
-  ensuring that all existing CheckTx are responded to and no new ones can
-  begin. After `Commit`, the mempool will rerun
-  CheckTx for all remaining transactions, throwing out any that are no longer valid.
-  Then the mempool will unlock and start sending CheckTx again.
-
-  Keys and values in Tags must be UTF-8 encoded strings (e.g.
-  "account.owner": "Bob", "balance": "100.0", "date": "2018-01-02")
-
-### DeliverTx
-
-- **Request**:
-  - `Tx ([]byte)`: The request transaction bytes.
-- **Response**:
-  - `Code (uint32)`: Response code.
-  - `Data ([]byte)`: Result bytes, if any.
-  - `Log (string)`: The output of the application's logger. May
-    be non-deterministic.
-  - `Info (string)`: Additional information. May
-    be non-deterministic.
-  - `GasWanted (int64)`: Amount of gas requested for transaction.
-  - `GasUsed (int64)`: Amount of gas consumed by transaction.
-  - `Tags ([]cmn.KVPair)`: Key-Value tags for filtering and indexing
-    transactions (eg. by account).
-- **Usage**:
-  - Deliver a transaction to be executed in full by the application.
-    If the transaction is valid, returns CodeType.OK.
-  - Keys and values in Tags must be UTF-8 encoded strings (e.g.
-    "account.owner": "Bob", "balance": "100.0",
-    "time": "2018-01-02T12:30:00Z")
-
-### EndBlock
-
-- **Request**:
-  - `Height (int64)`: Height of the block just executed.
-- **Response**:
-  - `ValidatorUpdates ([]ValidatorUpdate)`: Changes to validator set (set
-    voting power to 0 to remove).
-  - `ConsensusParamUpdates (ConsensusParams)`: Changes to
-    consensus-critical time, size, and other parameters.
-  - `Tags ([]cmn.KVPair)`: Key-Value tags for filtering and indexing
-- **Usage**:
-  - Signals the end of a block.
-  - Called prior to each Commit, after all transactions.
-  - Validator updates returned for block H:
-    - apply to the NextValidatorsHash of block H+1
-    - apply to the ValidatorsHash (and thus the validator set) for block H+2
-    - apply to the RequestBeginBlock.LastCommitInfo (ie. the last validator set) for block H+3
-  - Consensus params returned for block H apply for block H+1
-
-### Commit
-
-- **Response**:
-  - `Data ([]byte)`: The Merkle root hash
-- **Usage**:
-  - Persist the application state.
-  - Return a Merkle root hash of the application state.
-  - It's critical that all application instances return the
-    same hash. If not, they will not be able to agree on the next
-    block, because the hash is included in the next block!
-
-## Data Messages
-
-### Header
-
-- **Fields**:
-  - `ChainID (string)`: ID of the blockchain
-  - `Height (int64)`: Height of the block in the chain
-  - `Time (google.protobuf.Timestamp)`: Time of the block. It is the proposer's
-    local time when block was created.
-  - `NumTxs (int32)`: Number of transactions in the block
-  - `TotalTxs (int64)`: Total number of transactions in the blockchain until
-    now
-  - `LastBlockID (BlockID)`: Hash of the previous (parent) block
-  - `LastCommitHash ([]byte)`: Hash of the previous block's commit
-  - `ValidatorsHash ([]byte)`: Hash of the validator set for this block
-  - `NextValidatorsHash ([]byte)`: Hash of the validator set for the next block
-  - `ConsensusHash ([]byte)`: Hash of the consensus parameters for this block
-  - `AppHash ([]byte)`: Data returned by the last call to `Commit` - typically the
-    Merkle root of the application state after executing the previous block's
-    transactions
-  - `LastResultsHash ([]byte)`: Hash of the ABCI results returned by the last block
-  - `EvidenceHash ([]byte)`: Hash of the evidence included in this block
-  - `ProposerAddress ([]byte)`: Original proposer for the block
-- **Usage**:
-  - Provided in RequestBeginBlock
-  - Provides important context about the current state of the blockchain -
-    especially height and time.
-  - Provides the proposer of the current block, for use in proposer-based
-    reward mechanisms.
-
-### Validator
-
-- **Fields**:
-  - `Address ([]byte)`: Address of the validator (hash of the public key)
-  - `Power (int64)`: Voting power of the validator
-- **Usage**:
-  - Validator identified by address
-  - Used in RequestBeginBlock as part of VoteInfo
-  - Does not include PubKey to avoid sending potentially large quantum pubkeys
-    over the ABCI
-
-### ValidatorUpdate
-
-- **Fields**:
-  - `PubKey (PubKey)`: Public key of the validator
-  - `Power (int64)`: Voting power of the validator
-- **Usage**:
-  - Validator identified by PubKey
-  - Used to tell Tendermint to update the validator set
-
-### VoteInfo
-
-- **Fields**:
-  - `Validator (Validator)`: A validator
-  - `SignedLastBlock (bool)`: Indicates whether or not the validator signed
-    the last block
-- **Usage**:
-  - Indicates whether a validator signed the last block, allowing for rewards
-    based on validator availability
-
-### PubKey
-
-- **Fields**:
-  - `Type (string)`: Type of the public key. A simple string like `"ed25519"`.
-    In the future, may indicate a serialization algorithm to parse the `Data`,
-    for instance `"amino"`.
-  - `Data ([]byte)`: Public key data. For a simple public key, it's just the
-    raw bytes. If the `Type` indicates an encoding algorithm, this is the
-    encoded public key.
-- **Usage**:
-  - A generic and extensible typed public key
-
-### Evidence
-
-- **Fields**:
-  - `Type (string)`: Type of the evidence. A hierarchical path like
-    "duplicate/vote".
-  - `Validator (Validator`: The offending validator
-  - `Height (int64)`: Height when the offense was committed
-  - `Time (google.protobuf.Timestamp)`: Time of the block at height `Height`.
-    It is the proposer's local time when block was created.
-  - `TotalVotingPower (int64)`: Total voting power of the validator set at
-    height `Height`
-
-### LastCommitInfo
-
-- **Fields**:
-  - `Round (int32)`: Commit round.
-  - `Votes ([]VoteInfo)`: List of validators addresses in the last validator set
-    with their voting power and whether or not they signed a vote.
diff --git a/docs/app-dev/ecosystem.json b/docs/app-dev/ecosystem.json
deleted file mode 100644
index 9e264af2f..000000000
--- a/docs/app-dev/ecosystem.json
+++ /dev/null
@@ -1,200 +0,0 @@
-{
-  "abciApps": [
-    {
-      "name": "Cosmos SDK",
-      "url": "https://github.com/cosmos/cosmos-sdk",
-      "language": "Go",
-      "author": "Cosmos",
-      "description": "A prototypical account based crypto currency state machine supporting plugins"
-    },
-    {
-      "name": "cb-ledger",
-      "url": "https://github.com/block-finance/cpp-abci",
-      "language": "C++",
-      "author": "Block Finance",
-      "description": "Custodian Bank Ledger, integrating central banking with the blockchains of tomorrow"
-    },
-    {
-      "name": "Clearchain",
-      "url": "https://github.com/tendermint/clearchain",
-      "language": "Go",
-      "author": "FXCLR",
-      "description": "Application to manage a distributed ledger for money transfers that support multi-currency accounts"
-    },
-    {
-      "name": "Ethermint",
-      "url": "https://github.com/tendermint/ethermint",
-      "language": "Go",
-      "author": "Tendermint",
-      "description": "The go-ethereum state machine run as an ABCI app"
-    },
-    {
-      "name": "Merkle AVL Tree",
-      "url": "https://github.com/tendermint/merkleeyes",
-      "language": "Go",
-      "author": "Tendermint",
-      "description": "Tendermint IAVL tree implemented as an ABCI app"
-    },
-    {
-      "name": "Burrow",
-      "url": "https://github.com/hyperledger/burrow",
-      "language": "Go",
-      "author": "Monax Industries",
-      "description": "Ethereum Virtual Machine augmented with native permissioning scheme and global key-value store"
-    },
-    {
-      "name": "Merkle AVL Tree",
-      "url": "https://github.com/jTMSP/MerkleTree",
-      "language": "Java",
-      "author": "jTMSP",
-      "description": "Tendermint IAVL tree implemented as an ABCI app"
-    },
-    {
-      "name": "TMChat",
-      "url": "https://github.com/wolfposd/TMChat",
-      "language": "Java",
-      "author": "jTMSP",
-      "description": "P2P chat using Tendermint"
-    },
-    {
-      "name": "Comit",
-      "url": "https://github.com/zballs/comit",
-      "language": "Go",
-      "author": "Zach Balder",
-      "description": "Public service reporting and tracking"
-    },
-    {
-      "name": "ParadigmCore",
-      "url": "https://github.com/ParadigmFoundation/ParadigmCore",
-      "language": "TypeScript",
-      "author": "Paradigm Labs",
-      "description": "Reference implementation of the Paradigm Protocol, and OrderStream network client."
-    },
-    {
-      "name": "Passchain",
-      "url": "https://github.com/trusch/passchain",
-      "language": "Go",
-      "author": "trusch",
-      "description": "Tool to securely store and share passwords, tokens and other short secrets"
-    },
-    {
-      "name": "Passwerk",
-      "url": "https://github.com/rigelrozanski/passwerk",
-      "language": "Go",
-      "author": "Rigel Rozanski",
-      "description": "Encrypted storage web-utility backed by Tendermint"
-    },
-    {
-      "name": "py-tendermint",
-      "url": "https://github.com/davebryson/py-tendermint",
-      "language": "Python",
-      "author": "Dave Bryson",
-      "description": "A Python microframework for building blockchain applications with Tendermint"
-    },
-    {
-      "name": "Stratumn SDK",
-      "url": "https://github.com/stratumn/sdk",
-      "language": "Go",
-      "author": "Stratumn",
-      "description": "SDK for Proof-of-Process networks"
-    },
-    {
-      "name": "Lotion",
-      "url": "https://github.com/keppel/lotion",
-      "language": "Javascript",
-      "author": "Judd Keppel",
-      "description": "A Javascript microframework for building blockchain applications with Tendermint"
-    },
-    {
-      "name": "Tendermint Blockchain Chat App",
-      "url": "https://github.com/SaifRehman/tendermint-chat-app/",
-      "language": "Javascript",
-      "author": "Saif Rehman",
-      "description": "This is a minimal chat application based on Tendermint using Lotion.js in 30 lines of code!. It also includes web/mobile application built using Ionic 3."
-    },
-    {
-      "name": "BigchainDB",
-      "url": "https://github.com/bigchaindb/bigchaindb",
-      "language": "Python",
-      "author": "BigchainDB GmbH and the BigchainDB community",
-      "description": "Blockchain database"
-    },
-    {
-      "name": "Mint",
-      "url": "https://github.com/Hashnode/mint",
-      "language": "Go",
-      "author": "Hashnode",
-      "description": "Build blockchain-powered social apps"
-    }
-  ],
-  "abciServers": [
-    {
-      "name": "go-abci",
-      "url": "https://github.com/tendermint/tendermint/tree/master/abci",
-      "language": "Go",
-      "author": "Tendermint"
-    },
-    {
-      "name": "js-abci",
-      "url": "https://github.com/tendermint/js-abci",
-      "language": "Javascript",
-      "author": "Tendermint"
-    },
-    {
-      "name": "rust-tsp",
-      "url": "https://github.com/tendermint/rust-tsp",
-      "language": "Rust",
-      "author": "Tendermint"
-    },
-    {
-      "name": "cpp-tmsp",
-      "url": "https://github.com/mdyring/cpp-tmsp",
-      "language": "C++",
-      "author": "Martin Dyring"
-    },
-    {
-      "name": "jabci",
-      "url": "https://github.com/jTendermint/jabci",
-      "language": "Java",
-      "author": "jTendermint"
-    },
-    {
-      "name": "ocaml-tmsp",
-      "url": "https://github.com/zballs/ocaml-tmsp",
-      "language": "Ocaml",
-      "author": "Zach Balder"
-    },
-    {
-      "name": "abci_server",
-      "url": "https://github.com/KrzysiekJ/abci_server",
-      "language": "Erlang",
-      "author": "Krzysztof Jurewicz"
-    },
-    {
-      "name": "py-abci",
-      "url": "https://github.com/davebryson/py-abci",
-      "language": "Python",
-      "author": "Dave Bryson"
-    },
-    {
-      "name": "tm-abci (fork of py-abci with async IO)",
-      "url": "https://github.com/SoftblocksCo/tm-abci",
-      "language": "Python",
-      "author": "Softblocks"
-    },
-    {
-      "name": "Spearmint",
-      "url": "https://github.com/dennismckinnon/spearmint",
-      "language": "Javascript",
-      "author": "Dennis McKinnon"
-    }
-  ],
-  "aminoLibraries": [
-    {
-      "name": "JS-Amino",
-      "url": "https://github.com/TanNgocDo/Js-Amino",
-      "language": "Javascript",
-      "author": "TanNgocDo"
-    }
-  ]
-}
diff --git a/docs/app-dev/ecosystem.md b/docs/app-dev/ecosystem.md
deleted file mode 100644
index c87d3658b..000000000
--- a/docs/app-dev/ecosystem.md
+++ /dev/null
@@ -1,9 +0,0 @@
-# Ecosystem
-
-The growing list of applications built using various pieces of the
-Tendermint stack can be found at the [ecosystem page](https://tendermint.com/ecosystem).
-
-We thank the community for their contributions and welcome the
-addition of new projects. A pull request can be submitted to [this
-file](https://github.com/tendermint/tendermint/blob/master/docs/app-dev/ecosystem.json)
-to include your project.
diff --git a/docs/research/determinism.md b/docs/research/determinism.md
deleted file mode 100644
index b1c20566a..000000000
--- a/docs/research/determinism.md
+++ /dev/null
@@ -1,3 +0,0 @@
-# On Determinism
-
-See [Determinism](../spec/abci/abci.md#determinism).
diff --git a/docs/research/transactional-semantics.md b/docs/research/transactional-semantics.md
deleted file mode 100644
index c4b543328..000000000
--- a/docs/research/transactional-semantics.md
+++ /dev/null
@@ -1,5 +0,0 @@
-# Transactional Semantics
-
-See details of the [broadcast API](../tendermint-core/using-tendermint.md#broadcast-api)
-and the [mempool WAL](../tendermint-core/running-in-production.md#mempool-wal).
-
diff --git a/docs/spec/consensus/wal.md b/docs/spec/consensus/wal.md
index 6146ab9c0..889ce4868 100644
--- a/docs/spec/consensus/wal.md
+++ b/docs/spec/consensus/wal.md
@@ -1 +1,32 @@
-[Moved](../software/wal.md)
+# WAL
+
+Consensus module writes every message to the WAL (write-ahead log).
+
+It also issues fsync syscall through
+[File#Sync](https://golang.org/pkg/os/#File.Sync) for messages signed by this
+node (to prevent double signing).
+
+Under the hood, it uses
+[autofile.Group](https://godoc.org/github.com/tendermint/tmlibs/autofile#Group),
+which rotates files when those get too big (> 10MB).
+
+The total maximum size is 1GB. We only need the latest block and the block before it,
+but if the former is dragging on across many rounds, we want all those rounds.
+
+## Replay
+
+Consensus module will replay all the messages of the last height written to WAL
+before a crash (if such occurs).
+
+The private validator may try to sign messages during replay because it runs
+somewhat autonomously and does not know about replay process.
+
+For example, if we got all the way to precommit in the WAL and then crash,
+after we replay the proposal message, the private validator will try to sign a
+prevote. But it will fail. That's ok because we’ll see the prevote later in the
+WAL. Then it will go to precommit, and that time it will work because the
+private validator contains the `LastSignBytes` and then we’ll replay the
+precommit from the WAL.
+
+Make sure to read about [WAL corruption](../../tendermint-core/running-in-production.md#wal-corruption)
+and recovery strategies.
diff --git a/docs/spec/software/abci.md b/docs/spec/software/abci.md
deleted file mode 100644
index 6e17089f3..000000000
--- a/docs/spec/software/abci.md
+++ /dev/null
@@ -1,3 +0,0 @@
-# Application Blockchain Interface (ABCI)
-
-This page has [moved](../abci/apps.md).
diff --git a/docs/spec/software/wal.md b/docs/spec/software/wal.md
deleted file mode 100644
index 889ce4868..000000000
--- a/docs/spec/software/wal.md
+++ /dev/null
@@ -1,32 +0,0 @@
-# WAL
-
-Consensus module writes every message to the WAL (write-ahead log).
-
-It also issues fsync syscall through
-[File#Sync](https://golang.org/pkg/os/#File.Sync) for messages signed by this
-node (to prevent double signing).
-
-Under the hood, it uses
-[autofile.Group](https://godoc.org/github.com/tendermint/tmlibs/autofile#Group),
-which rotates files when those get too big (> 10MB).
-
-The total maximum size is 1GB. We only need the latest block and the block before it,
-but if the former is dragging on across many rounds, we want all those rounds.
-
-## Replay
-
-Consensus module will replay all the messages of the last height written to WAL
-before a crash (if such occurs).
-
-The private validator may try to sign messages during replay because it runs
-somewhat autonomously and does not know about replay process.
-
-For example, if we got all the way to precommit in the WAL and then crash,
-after we replay the proposal message, the private validator will try to sign a
-prevote. But it will fail. That's ok because we’ll see the prevote later in the
-WAL. Then it will go to precommit, and that time it will work because the
-private validator contains the `LastSignBytes` and then we’ll replay the
-precommit from the WAL.
-
-Make sure to read about [WAL corruption](../../tendermint-core/running-in-production.md#wal-corruption)
-and recovery strategies.