Nowadays, there are only a few github repo that are still maintained that has something to do with Provably Fair Bitcoin gambling. Most of the sites hire their own developers to code their site and the codes are usually kept in private. Most if not all repo you see on github are either defunct, abandoned, not maintained, clone or with backdoors. So be careful in using any of them.
Some examples:
https://github.com/RHavar/pevpot - provably fair lottery that is made by RHavar but is now defunct and not maintained.
https://github.com/Bitsino/BitsinoDice - another defunct site and abandoned project.
https://github.com/popmanhe/Node_Dice - another repo that has potential but is now abandoned
https://github.com/felinegambler/CryptoBlackJack - an infamous clone of blackjack script made by johny1976,
**possible with backdoors**https://github.com/felinegambler/CryptoDice - same as above and with
**possible backdoors**Special Mention:(Moneypot.com scripts)
https://github.com/untitled-dice/untitled-dice.github.io - is the famous dice template for Moneypot but is not maintained anymore and may not work with new api of MP.
https://github.com/Dexon95/bitsweeper - is also a script for Moneypot that was made by Dexon.
IMO, do not use any of the repos that you might find, just check them out, understand it, take ideas from it and build your own.If you can't code your own, your best bet is to hire someone to code it for you. But becareful when buying scripts or hiring someone. Learn from the recent scam of Bitbox where they sold ready made sites which has alot of bugs and eventually scamming their clients.
Cheers,
-Uni
Bitsler.com Developer