The Community TFS Custom Activities project provides a place for build engineers to share workflow activities, build process template files, PowerShell scripts and tools for Team Foundation Build.
This project has been transitioned to a new home on GitHub from its orignal home on Codeplex https://tfsbuildextensions.codeplex.com/.
With the updated release cadence of Visual Studio, we plan to actively develop for v.Current and v.Next (as previews become available). The Codpelex project will remain for the foreseeable future but all 2013 and future dev will happen here.
For documentation on using the activities please see the Wiki on this project https://github.com/tfsbuildextensions/CustomActivities/wiki