Download the latest Bitcoin Cash compatible release of Bitcoin Unlimited (1.4.0.0, August 17th, 2018) from:

https://www.bitcoinunlimited.info/download

This release is a major release which is compatible with the Bitcoin Cash compatible with the Bitcoin Cash specifications you could find here:

• https://github.com/bitcoincashorg/bitcoincash.org/blob/master/spec/uahf-technical-spec.md (Aug 1st '17 Protocol Upgrade)
• https://github.com/bitcoincashorg/bitcoincash.org/blob/master/spec/nov-13-hardfork-spec.md (Nov 13th '17 Protocol Upgrade)
• https://github.com/bitcoincashorg/bitcoincash.org/blob/master/spec/may-2018-hardfork.md (May 15th '18 Protocol Upgrade)

A subsequent release containing the implementation of the November 2018 specification will be released soon after this one.

List of notable changes and fixes to the code base:

• Graphene Relay: A protocol for efficiently relaying blocks across a blockchain's network (experimental, turned off by default, set use-grapheneblocks=1 to turn it on, spec draft )
• blocksdb: Add leveldb as an alternative storage method for blocks and undo data (experimental, on-disk blocksdb data formats may change in subsequent releases, turned off by default)
• Double Spend Relaying
• BIP 135: Generalized version bits miners voting
• Clean up shadowing/thread clang warn
• Update depends libraries
• Rework of the Bitcoin fuzzer command line driver tool
• Add stand alone cpu miner to the set of binaries (useful to showcase the new mining RPC calls, provides a template for development of mining pool software, and is valuable for regtest/testnet mining)
• Cashlib: create a shared library to make creating wallets easier (experimental, this library factors useful functionality out of bitcoind into a separate shared library that is callable from higher level languages. Currently supports transaction signing, additional functionality TBD)
• Improve QA machinery (travis mainly)
• Port Hierarchical Deterministic wallet (BIP 32)
• add space-efficient mining RPC calls that send only the block header, coinbase transaction, and merkle branch: getminingcandidate, submitminingsolution

Release notes: https://github.com/BitcoinUnlimited/BitcoinUnlimited/blob/dev/doc/release-notes/release-notes-bucash1.4.0.0.md

Ubuntu PPA repository for BUcash 1.4.0.0 has been updated