Piazza displays the portraits of the programmers responsible for a build. It determines who is responsible by looking for nicknames the commit comments. This means that programmers must identify who worked on a commit in the commit message when they check their changes into source control. This feature encourages programmers to write good commit messages and, if pair programming. identify both members of the pair responsible for every change.

A Piazza-compatible commit message looks something like:

Alice and bob added Javascript animation effects to the web front-end

If suitably configured, Piazza will then show the portraits of Alice and Bob while Team City builds and tests their changes.

To configure the portraits displayed for each team member create a text file named portraits.cfg in the Team City configuration directory for the project. On Unix that is usually $HOME/.BuildServer/config/<project>/portraits.cfg when logged in to the account that runs the Team City server.

Each line of the file contains a comma separated list of the nicknames of a team member, followed by an equals symbol ("="), followed by the URL of the portrait for that team member. Here's an example:

alice = http://teamserver/alice.png
robert, bob = http://teamserver/bob.png

I've found South Park Studio to be a good tool for quickly creating portraits for Piazza. On Linux, you could use MeMaker.