The source code for Ash is available on Github and is released under the MIT license. That means that you can do what you wish with the code, but you must retain the original license, including the copyright notice, when distributing the source code as code or as a precompiled library. There is no requirement to mention Ash in your game but some developers do choose to credit Ash in their finished game, which is nice.
No libraries are required for using Ash. But Ash includes extensions for optional integration with