I've been out of the C++ game for about 10 years and I want to get back in and start on a commercial app. What libraries are in use these days?
I looking to be cross-platform compatible (as much as possible out-of-the-box).
What libraries to do you rely on? What features do they provide that make them "indispensable"?
See my answer below for a summary.
Cross-platform libraries that are free for commercial (or non-commercial) applications
Feel free to expand this list
Links to additional lists of open source C++ libraries: