Finding the process template for a your TFS 2015 projects
If you're trying to determine what Process Template was used when the projects in a given TFS project collection were created, the quickest way to do this that I've found is to run the following query against the SQL database for the TFS project collection:
SELECT P.[ProjectName], SQ.[value] [ProcessTemplate] FROM [dbo].[tbl_Project] P LEFT JOIN ( SELECT [name], [value], [project_id] FROM [dbo].[tbl_project_properties] WHERE [name] = 'Process Template' ) SQ ON P.ProjectUri LIKE '%' + CAST(SQ.[project_id] AS NVARCHAR(36)) + '%'
This query was written against TFS 2015 so may, or may not, work against other versions. There may even be a better/easier way to do this!
My skillset has matured somewhat since then, which you'll probably see from the posts here. You can read a bit more about me on the about page of the site, or check out some of the other posts on my areas of interest.