XT is an altcoin, do NOT use it.
XT doesn't even have the Hard fork code added as of yet and even if it did it wouldn't be considered an ALT until after the hard fork.
"So...
... maybe there's a misunderstanding on what I'm actually working on. I'm coding a hard-fork that will only fork:
-After March 1, 2016
-If 75% of hashing power is producing up-version blocks
-AND after some brave miner decides to actually produce a >1MB block.
It will be very difficult for anybody to lose money. Even if we assume that some stubborn minority of miners decides not to upgrade (in spite of Bitcoin Core warning them first that the chain consists mostly of blocks with up-version version number, and then warning them that there is an alternative invalid higher-work chain), those miners will be the only people who will lose money. Ordinary, SVP-using users will follow the longest chain, and since at least 75% of hashing power will be on the bigger-block chain, there is no chance of them losing money. The big-block-rejecting-chain will very, very quickly be left behind and ignored.
There will NOT be two active chains, that is just FUD. Anybody running old code will have to willfully ignore the warnings to upgrade to stay on the old chain, and the incentives are so strong to follow the majority I can't imagine the 1MB chain persisting for any significant length of time.
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I'm happy to tweak the parameters. The code I'm writing regression tests for right now is:
-8MB max block size (chinese miners were unhappy with 20 for not-entirely-clear reasons)
-Earliest fork date 11 Jan 2016 (miners and others want sooner rather than later)
-Activation when 750 of last 1,000 blocks are up-version (version 0x20000004 to be compatible with sipa's new versioning bits scheme)
-2 week 'grace period' after 75% threshold reached before first >1MB block allowed to be mined
-8MB cap doubles every two years (so 16MB in 2018, etc: unless there is a soft fork before then because 16MB is too much)
The code for all that is starting to get right on the edge of "too complicated for consensus," but the individual pieces are all straightforward. I'll write a BIP when I'm done with the code, and, as I've said repeatedly, I'm not stuck to any particular set of parameters."
https://www.reddit.com/r/Bitcoin/comments/39ziy6/eli5_what_will_happen_if_there_is_a_hard_fork/cs7xe9oGavin seems to be more reasonable than Mike on this topic and it will be great to see the Formal BIP submitted along with Garzik's BIP 100 and other soon to be pitched proposals. While I think 8MB is entirely reasonable one immediate problem I find with Gavin's plan is with incorporating an automatic doubling of the limit every 2 years which may encourage us to take the easy way out and allow blocks to naturally grow without any urgency to implement other solutions like the lightning network. Peter Todd does make some valid criticisms and we should be careful not to continue to kick the can down the road. 8MB is likely needed however to buy us some time to test other proposals and fix transaction malleability.