Private development is done in GitLab which free and more convenient. The codes for cross-chain transfer protocol, updates to Geth codebases.
ReplyBlock is privately developed on Gitlab. But these softwares are actually running on the testnet and production (ReplyBlock) already.
Tomochain, Tomo Governance DApp, Block Explorer publish the source code on: https://github.com/tomochain
. We released ICO smart-contract codes, container codes for building node and joint testnet, slides for tomochain roadmap, cross chain transfer demo codes. It should be clear that we are having private repos, and publish codes publicly when they are ready for public, or need to be audited.
We chose the model our team are comfortable with. Publishing work-in-progress is not suitable for us atm for multiple reasons including inviting unnecessary distractions, designing needs a to be done before coding. Protecting and auditing important codes are also more responsible, until the team reaches a certain scale.
We are also working with some third parties who we signed NDA (non disclosure agreement) for the codes developed.