I vote to accept GIL into boost. I am sorry I don't have time to write a more in-depth review at this point. ***What is your evaluation of the design?*** The design is very well thought out and seems surprisingly mature for a new library. ***What is your evaluation of the implementation?*** Convoluted and confusing, but there likely isn't a better way. ***What is your evaluation of the documentation?*** If I have one complaint about GIL its about the documentation. The tutorial is good, and so is the reference material ***What is your evaluation of the potential usefulness of the library?*** Extremely useful. While there are not as many algorithms as I would like, GIL by itself provides a remarkably stable base to build upon. I think it is really important that this is incorperated into boost because a lot of good things can be built off it. ***Did you try to use the library? With what compiler? Did you have any problems?*** GCC. My only problem was debugging templated code is hard, but I don't blame that on GIL. ***How much effort did you put into your evaluation? A glance? A quick reading? In-depth study?*** I have been using GIL as now for a few months as a part on a project on image compression. ***Are you knowledgeable about the problem domain?*** Moderately so.