Where is OS software required to be available at?
If I didn't want to use GitHub or Bitbucket, can I simply put it on my website? Where does the code have to reside in order to meet OS licensing?
Is it required to be hosted at all?
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Sign up to join this communityWhere is OS software required to be available at?
If I didn't want to use GitHub or Bitbucket, can I simply put it on my website? Where does the code have to reside in order to meet OS licensing?
Is it required to be hosted at all?
Different licenses have different requirements, but those requirements typically fall in these categories
Some licenses require different forms of source code distribution depending on how the binaries are distributed. In most cases, the requirements for source code distribution can also be met by including the source code in the same distribution as the binaries.
If the binaries are available for public download, then it is common to have a similar download link for the source code, or to provide a link to a publicly accessible repository for obtaining the source code.
The last option is mostly used with consumer electronics that contain open-source software.
If you are the sole copyright holder: You don’t have to distribute the source code at all. Even if the license you chose says that the source code must be provided to people that received the application, this requirement doesn’t apply to you.
If you aren’t the sole copyright holder: You must follow what the license says. Each license can have different requirements. Bart van Ingen Schenau’s answer lists some typical cases.
Two examples:
GPL 3: This license requires to offer the source code if distributing the binary.
Section 6 lists five options how the source code may be offered. If providing the binary as download from a website, option d) applies (tl;dr: can be hosted on your own or on someone else’s server).
Note that it’s not required to provide access to a repository (with change records). But it’s required to provide the source code of each version ever distributed, not only of the most recent one.
Apache 2.0: This license doesn’t require to offer the source code.
The OP has clarified that (s)he means "if I start my Open Source project, is there somewhere in particular I have to host it in order for it to lawfully be Open Source", and that seems a question worth answering.
The answer is no. In these days of Infrastructure-as-a-Service (IaaS) there are lots of sites that will provide the hosting engine for you. Most will provide at least some of the associated infrastructure also - mailing lists, IRC fora, licence clarification, vanity domain hosting, and so on - and of course they come with a community, so it's arguably more likely your project will be found by other people if it's on one of them. But your decision about hosting should be driven by what's right for you and your project. There are no other rules.
You also ask
Is it required to be hosted at all?
which is an interesting question. You are by no means required to distribute it, since you wrote it, but if you don't it's not meaningfully "open source" as no-one else can copy / distribute / modify it. In order for other people to get it, they'll have to get it from somewhere, and that will require some kind of hosting.