AcitveSpace uses Maven as its build tool. If you don't fancy using Maven you can use your IDE directly or Download a distribution or JAR.
We have tested the build with Maven 1.0 and it works fine. Later versions of Maven may vary - if you hit problems on other versions please talk to us on the mail lists.
If you prefer to use an IDE then you can autogenerate the IDE's project files using maven plugins. e.g.
Please refer to the plugin reference for more details on using them.