Xtrabytes OTS code has been published to Github:

https://github.com/XTRABYTES/XTRABYTES-OTS

"The code enables the understanding of XTRABYTES-OTS logic through code analysis. This is a usable and working solution for creating secret keys, public keys, and signatures for XTRABYTES-OTS and also for signing and validating the messages. This published post-quantum OTS signature method also will test voluntary works. If the community teamwork will powerful and usable in this way then many other XTRABYTES technology bricks will be published similar way. Explanatory parts are missing from the code, these comment parts will have to be added during volunteer work so that even those less experienced in coding can understand the logic of the operations. Detailed documentation containing explanatory images based on the code can also be prepared so that even those who do not know how to program can understand the operation of XTRABYTES-OTS. Related to these documents, high-level professional evaluations and mathematical proofs related to the XTRABYTES-OTS technology can also be prepared." - Borzalom

Here's an article to understand what OTS is:
https://www.cryptologie.net/article/306/hash-based-signatures-part-i-one-time-signatures-ots/

Please visit the Discord for additional information: https://discord.gg/PQbYbwpQXr