SPSS Community at IBM's developerWorks portal
The community of SPSS users (or, better say, users of IBM's SPSS family products), which is supported by the vendor. You'll find here technical papers, help and downloads not only for IBM SPSS Statistics, but also for IBM SPSS Modeler, IBM SPSS Collaboration & Deployment Services, and IBM SPSS Data Collection — major members of SPSS family. You may read the forums and, after a short registration procedure, you may post there. Many topics are related to programmability in SPSS. Downloads include R, Python and .NET integration plugins, utilities and extension commands which you could download, install and use in Statistics GUI or syntax as any other regular command.
Link added: Feb. 3, 2015