Robust and mature SIP stacks which are still maintained are a rarity these days. I was pleasantly surprised recently to learn just how well this very mature library is being maintained. It seems like a great deal of effort has been invested to keep both the code and feature set relevant and up to date. Kudos to the maintainer.
Most other open source SIP stacks available either don't have the feature depth and breadth required for a serious SIP project: are only usable from a specific programming language, have been long abandoned, or have impermissive licenses.
Most other open source SIP stacks available either don't have the feature depth and breadth required for a serious SIP project: are only usable from a specific programming language, have been long abandoned, or have impermissive licenses.