Nothing that I could not re-license again later. I lost the patents in progress as I didn’t have the resources to continue with them, but this was actually a blessing in disguise. Rather than protecting the IP by patents I was forced to concentrate on trade secrets which if you have the choice is a much better way to go.
If anyone is interested in learning more I wrote a rather long blog post about the whole experience [1].
I was in a situation where angry clueless investors wanted to keep the software as an asset they were entitled to, but it was close to worthless without the engineering knowledge. They tried to shop the MVP around but got nowhere. If I could have kept it I would have tried to keep it running on the side.
One of the best comments I ever heard was from a Windows engineer talking about a source code leak several years back: "Sure, but how are they going to build it?"
Surely this developer meant that the leaked code had many dependencies on libraries that were proprietary to M$. That would make it difficult to build but this scenario is likely unique to partial code leaks at large companies.
Even a complete code leak can be near unbuildable without knowledge of how to set up a build environment. A number of years back a product i work on was so difficult to build it was a two day effort to set up a new developer workstation with the help of the existing team. Someone with just a full code dump would have taken weeks.
I read (old new thing probably -- a long time ago) that windows had circular dependencies until relatively recently. A large-ish team spent half a decade untangling it. Good luck building 40mm lines of source for a 25 year old project without detailed instructions...
Sure if your investors are going to be idiotic about the situation then this might not be possible, but it is an option worth exploring and in my case it worked out well.
If anyone is interested in learning more I wrote a rather long blog post about the whole experience [1].
1. http://www.tillett.info/2015/06/24/why-i-kept-my-startup-in-...