Forked from Xbox Media Center to build a client-server streaming model. Became a massive commercial product.
Plex is a client-server media streaming platform. The Plex Media Server (originally based on XBMC, now completely rewritten) handles media indexing, metadata retrieval, transcoding, and streaming. Clients exist for virtually every platform: iOS, Android, smart TVs, web browsers, game consoles, and streaming devices. The server transcodes video and audio in real-time to match client device capabilities, enabling seamless streaming over local networks and the internet.
Plex is the rare fork that doesn't just survive — it becomes a massively successful commercial product that eclipses its parent project in every measurable way. It's also a fork that the open source community has complicated feelings about, because it took community-built code and turned it into a proprietary empire.
It started in late 2007 when Elan Feingold, a developer who wanted a media center for his Mac, began porting XBMC (Xbox Media Center) to Mac OS X. XBMC was an open source media player originally built for the original Xbox, and it had a passionate community but was primarily Linux-focused. Around the same time, Cayce Ullman and Scott Olechowski — software executives fresh from selling their company to Cisco — noticed Feingold's work in the XBMC forums and reached out. In January 2008, the three-person team formed.
They collaborated with the XBMC project until May 21, 2008, when divergent goals forced a split. The XBMC team was focused on building the best local media player; Feingold and company wanted to build a client-server architecture that could stream media across devices and networks. They forked the code, named it Plex in July 2008, and Plex, Inc. was incorporated in December 2009.
The pivot that made Plex was the client-server model. Rather than being a standalone media player like XBMC (later renamed Kodi), Plex split into a server component that transcodes and serves media and lightweight clients on every platform imaginable — phones, tablets, smart TVs, game consoles, streaming sticks. Your media library became accessible anywhere, and Plex handled the messy work of transcoding video to match each device's capabilities.
Plex grew into a legitimate business, raising venture funding and eventually adding an ad-supported free streaming service, live TV integration, and music streaming. The open source roots became increasingly distant as the server component went proprietary. Kodi (XBMC) and Plex now occupy completely different niches: Kodi is the open source purist's local media player, while Plex is the polished commercial product your non-technical friends actually use.
Elan Feingold begins porting XBMC to Mac OS X
Ullman and Olechowski join Feingold to form three-person team
Code officially forked from XBMC due to divergent goals
Project officially named Plex
Plex, Inc. incorporated with Ullman as CEO, Feingold as CTO
Plex Media Server rewritten, moving away from XBMC/Kodi codebase
XBMC renamed to Kodi, distancing from Xbox origins
Plex launches ad-supported free streaming service
Plex continues as major commercial media platform with millions of users
Plex is arguably the most commercially successful open source fork ever created. It defined the personal media server category and brought media streaming to mainstream users who would never touch Kodi or a Linux box. The client-server architecture it pioneered influenced how the entire industry thinks about personal media libraries.
For the open source community, however, Plex represents an uncomfortable reality: the most successful outcome of an open source fork was to become a proprietary product. The XBMC/Kodi community watched their code become the foundation of a venture-funded company that eventually closed its source. Whether this is a success story or a cautionary tale depends entirely on your perspective on open source philosophy.