Top Rated for TeamCity

TFS WorkItem

TFS workitems issue tracker integration.

Visual Studio Online Work Items

provides integration with Visual Studio Team Services as an issue tracker ( since TeamCity 10.0, an alternative implementation is bundled).

Server Profiling

Can be used for detailed investigation for TeamCity server performance problems. The data collected is to be sent to TeamCity support.

JSON API

API to emulate Hudson's JSON one, e.g.

PyTeamCity

Python interface to the TeamCity REST API.

Ruby REST client

a Ruby wrapper for the TeamCity Rest API.

Sharp2City

a .Net API for the TeamCity REST API ( announcement).

SwiftCity

TeamCity REST API client in Swift.

TeamCityCLI

CLI for TeamCity REST API.

TeamCitySharp

a .NET Library to access TeamCity via the REST API (newer take).