Although incomplete sections of it were previously available through EA's GPL source code releases, the EA STL is now officially open sourced, under a modified BSD license. Like everything nowadays, it lives on GitHub:
https://github.com/electronicarts/EASTL
If you're new to this or have generally forgotten what's going on, here is an overview of why this exists:
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2271.html