The last version of the source code is available from http://community.jaspersoft.com/project/jaspersoft-studio/releases by clicking Browse Source Code, which lets you access the Subversion (SVN) repository (read only mode) where the most up-to-date version is available. You can download and compile this source code, but since it is a work in progress it might contain new, unreleased features and bugs. All the information necessary to download the Source Code, configure a develop environment on the Eclipse IDE and compilerun the source code are described in the tutorial Contributing to Jaspersoft Studio and building from sources.