I am hoping to build an online game platform that will enable umpires and authorised players to talk to each other via VoIP, plus send/receive text messages. There is no need to connect with handsets, communication between PCs will suffice.
The software needs to be Open Source as I will want to modify the code; it should also be web-based so as to minimise the deployment/support issues.
What packages do you recommend? sipml5.org looks promising for example but it is new and I know very little about it.
Please note that I am fairly new to the VoIP world but I do have extensive programming experience; my preferred language is Python but that is not suitable for inline web development.