Is it possible for a developer to lose rights to work on a self-created, open-source-licensed project after an outside company, developer, or organization copyrights (or takes some other legal action regarding) the same project?I haven't heard of this happening, but it seems entirely possible that someone could independently develop a project and then have the rights to continue working on said project (or an idea/language/technology) taken away...For example, when a project like Minecraft (but open-source-licensed, in this case,) is developed, and is later bought by a company like Microsoft, does this mean that Microsoft can say that Mojang (or Notch, for that matter,) no longer has rights to work on further Minecraft development?Another example would be Oracle who bought the open-source MySQL database.In other words, are copyrights still necessary for intellectual property alongside open source licensing?
Open Source Licensing and Intellectual Property Rights
licensing;open source;copyright;intellectual property
Minecraft is actually an invalid example, as it was a proprietary commercial project.  If Microsoft purchases the IP rights to the project, and does not keep the Mojang developers on, then it's no different from any other proprietary project: you don't own the rights to what you work on, under work made for hire doctrine.Having said that, for an actual open-source project, things are different.  When source code is released under a license, the genie can't be put back into the bottle.  There's a legal doctrine known as promissory estoppel which, in layman's terms, says that but you promised! is actually a valid legal argument, and so when someone publishes source code and says here you go, community, use this as an open-source project, they can't take that back.One of the most dramatic examples of this is the Firebird database.  A long time ago, Borland decided to release the source code to their InterBase RDBMS, but then, for whatever reason, they quickly had a change of heart.  But because the code had already been published, they couldn't take that back, and a development community continued to work on the InterBase source under the new name Firebird.  Today, Firebird and InterBase are two similar but distinct products, both still under active development, one by the open-source community and the other as a commercial project run by Embarcadero, who bought the rights from Borland.(Standard disclaimer: I am not a lawyer.  This is not legal advice.  This is just stuff I've picked up based on common sense and experience.)