Download the latest Bitcoin Cash compatible release of Bitcoin Unlimited (1.5.1.0, December 20th, 2018) from:

https://www.bitcoinunlimited.info/download

This is a major release version based of Bitcoin Unlimited 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)
• https://github.com/bitcoincashorg/bitcoincash.org/blob/master/spec/2018-nov-upgrade.md (Nov 15th '18 Protocol Upgrade)

List of notable changes and fixes to the code base:

• 10x transaction processing performance
• Extended version message: xversion
• Adding a checkpoint at height 556767 both for the SV and the BCH chain
• Reduce Graphene and Xthin preferential timer to 1 second default (it could also be disabled)

Release notes: https://github.com/BitcoinUnlimited/BitcoinUnlimited/blob/dev/doc/release-notes/release-notes-bucash1.5.1.0.md

PS Ubuntu PPA repository for BUcash 1.5.1.0 will be updated later today.