Why is this useful? It's very easy to compile and install PHP. Just as easy as it is to compile and install anything on *nix ... cd dir && configure && make && make install ...
The problem tends to be not only compiling PHP itself but the myriad of dependencies for modules, so I assume the project also simplifies the process of downloading and installing those. This is similar to what the BitNami LAMPStack installer does for Linux, Windows and Mac (disclaimer, I am one of the developers). We provide self-contained, binary installable packages of Apache, MySQL, PHP and all of its dependencies http://bitnami.org/stack/lampstack
Currently it does not solve the problem of the sh*tload of dependencies, though I'm filing an issue for now.
php-build currently solves mainly the problem of configuring PHP correctly, so the build is isolated to the prefix it's installed in (it also sets up PEAR or Pyrus correctly).
Just as easy as it is to compile and install anything on nix ...*
I hope that's tongue-in-cheek, because compilation is definitely non-trivial for any sophisticated piece of software with lots of external dependencies, especially if they're not available in the package manager that happens to come with the distro you're running at the moment (and it's even harder if you don't have sudo/root access on your box).
The mission of php-build is to reduce my workflow of testing new PHP versions to one command I can run. php-build also provides a opinionated default configuration, which you can build on and extend.
Without php-build I have to do this when I want to test, for example PHP 5.4.0RC1:
1. Find a tarball
2. Extract Tarball
3. Configure it
3a. If I already have a script to configure this version go to 4.
3b. Pick configure options (PHP has a sh*tload of them)
3c. See if it works
4. make && make install
5. install Pyrus
6. install XDebug
7. install PHPUnit
So with php-build (and php-build-plugin-phpunit):
1. php-build -i development 5.4.0rc1 ~/.phpenv/versions/5.4.0rc1
2. ?
3. Profit
I'd really like to see on the homepage which operating systems this works with/has been tested with. They're obviously using some sort of nix in the examples...but does it work with every nix (including Mac OS X)?
