Much confusion here. There are three different Matrix projects related to libpurple:
https://github.com/matrix-org/purple-matrix is a very basic proof-of-concept PRPL plugin that lets a libpurple client like Pidgin or Adium or Purism's Chatty connect to Matrix. We wrote it as a demo to inspire others hoping that someone from the Pidgin community might pick it up and polish it, but sadly there hasn't been much progress. We don't have bandwidth to finish it off ourselves.
Then there was matrix-appservice-purple (https://github.com/matrix-org/node-purple/tree/f5ad4ef798904...), which was a proof of concept bridge using node-purple which let Matrix connect to anything that libpurple can speak. We used it to demo bridging from Matrix into Skype via the skypeweb PRPL - but it was a very fragile quick hack demo.
Then this was replaced by Bifrost, a proper production-grade bridge engine: https://github.com/matrix-org/matrix-bifrost. It supports different plugins for the bridging, one of which is libpurple via node-purple (although most people use it as an XMPP bridge, via the xmpp.js plugin). This lets you connect from Matrix into any protocol supported by libpurple - effectively an equivalent of Bitlbee, but for Matrix rather than IRC.
https://github.com/matrix-org/purple-matrix is a very basic proof-of-concept PRPL plugin that lets a libpurple client like Pidgin or Adium or Purism's Chatty connect to Matrix. We wrote it as a demo to inspire others hoping that someone from the Pidgin community might pick it up and polish it, but sadly there hasn't been much progress. We don't have bandwidth to finish it off ourselves.
Then there was matrix-appservice-purple (https://github.com/matrix-org/node-purple/tree/f5ad4ef798904...), which was a proof of concept bridge using node-purple which let Matrix connect to anything that libpurple can speak. We used it to demo bridging from Matrix into Skype via the skypeweb PRPL - but it was a very fragile quick hack demo.
Then this was replaced by Bifrost, a proper production-grade bridge engine: https://github.com/matrix-org/matrix-bifrost. It supports different plugins for the bridging, one of which is libpurple via node-purple (although most people use it as an XMPP bridge, via the xmpp.js plugin). This lets you connect from Matrix into any protocol supported by libpurple - effectively an equivalent of Bitlbee, but for Matrix rather than IRC.