Most other projects probably would have called the product "1.0" much earlier, but we deliberately decided to delay that label as long as possible. Such limitations are always documented in the release notes of our releases.
We were aware that many people were waiting for a 1.0 before using Subversion, and had very specific expectations about the meaning of that label. The client and server are designed to work as long as they aren't more than one major release version apart. Our client/server interoperability policy is documented in the "Compatibility" section of the Subversion Community Guide.
The Subversion server can also be run on any platform where APR runs, but cannot host a repository on Win95/Win98/Win Me. The "Subversion Filesystem" is not a kernel-level filesystem that one would install in an operating system.
Instead, it is Subversion's repository interface, which is a "versioned filesystem" in the sense that it stores a directory tree whose state is remembered from revision to revision.
(This is similar to how branches and tags are conventions built on top of copies, instead of being basic concepts built into Subversion itself.) Each time you commit a change, the repository stores a new revision of that overall repository tree, and labels the new tree with a new revision number.
Of course, most of the tree is the same as the revision before, except for the parts you changed.
In other words, you are free to download, modify, and redistribute Subversion as you please; no permission from any company or any person is required. It is mature software, with strong compatibility guarantees.Thus, the advancing revision number marks the progress of the repository as a whole; you generally can't gauge the progress of a particular project within the repository by watching the revision number.Also, the revision number should not be used as the publicly-visible release number of a particular project in the repository.Copyright © 2017 The Apache Software Foundation, Licensed under the Apache License, Version 2.0.Apache, Apache Subversion, and the Apache feather logo are trademarks of The Apache Software Foundation.Writing programs to access the repository is similar to writing programs that use other filesystem APIs.