Maps I've made for Left 4 Dead 2.
Go nuts. Feel free to use all, some or none of the files provided here for whatever purpose you see fit (distribution, modification, compilation...), with or without credit, as long as you're not selling the work they were used for. That any resulting derivative works retain these conditions is preferred, but not required.
TLDR: Use, fix, learn and let others learn.
These rules (or lack of) apply to all my work that's in the public domain, unless specified otherwise.