I think a lot of the time when people at companies look at this sort of thing they get trapped in a somewhat unnecessary chicken and egg problem. Yes, that proj

I think a lot of the time when people at companies look at this sort of thing they get trapped in a somewhat unnecessary chicken and egg problem. Yes, that project is full of cruft and only one guy knows how to build it, but if you've got people on the outside actually willing to do the work to carve it out into something useful, and you have no issue beyond embarrassment to not let them, you should just jump on that opportunity and make it happen. Do a source dump, cutting out the proprietary bits you can't release without fixing them and give it to the people who claim they can make it happen. Make someone available to spend an hour every now and then answering questions they have as they figure it out. If they succeed at re-modularizing it into something useful, open source that and look at how you can 'bring it home' into your original project. There are people out there who excel at these kinds of de- and re-integration work. The reality is that no matter how much work you put into open sourcing that thing yourself before it's 'ready' and no longer embarrassing to you, you will never have any guarantee it'll pick up a community and be useful to people outside your company. This is why you shouldn't wait for that condition, because the cost of that work will never meet the average return on investment to open sourcing. But it may be worth the work to someone else.