Where can I find a file format spec, or guidance for parsing, .suo files? I'd like to extract breakpoint information from them.
The MSDN topic Solution User Options (.Suo) File briefly describes how storage streams are read from and written to this structure storage file, but this information is very scant, especially for someone of my structured storage experience.
There's little hope to ever get any useful info out of a .suo file. Even if you do manage to reverse-engineer its (complicated) format, your hard work will be for naught with the next release or service pack for Visual Studio.
The file stores IDE state. That state is also accessible from the extensibility interfaces. Use macros to get ahead. Lookup the EnvDTE namespace in the MSDN library to get started.