Hi!
Supported development OSes: Windows, Mac OS X, Linux, FreeBSD
Supported target OSes: Windows, Mac OS X, Linux
There are ActiveX and NPAPI browser plug-ins. WebGL support is in the works. Native iOS and Android ports are in a proof-of-concept state and not being actively developed at the moment.
When the engine was created is a point of debate. The set of libraries that eventually became Panda3D was developed somewhere in the 90s, but many parts of the engine were rewritten later. I believe the first public open-source release was around 2002, I believe.
Panda3D is open-source and free for any purpose. This makes it a good fit for indie game developers, who often don’t have a big budget to spend on commercial engines.
I don’t keep track of market trends, but Panda3D seems to still enjoy active use by the open-source gamedev community, even if it had to trade in a little bit of terrain to commercial engines in the indie gamedev scene, presumably due to some commercial engines having recently begun to offer more interesting pricing options to indie gamedevs. Panda3D is still a favourite among those that are looking for free and open-source game engines, however.