TeamCity installation package is identical for both Professional and Enterprise Editions and is available for download at http://www.jetbrains.com/teamcity/download/ page.
Following packages are available:
Target
Download
Note
Windows
TeamCity<version number>.exe
Executable Windows installer bundled with Tomcat and Java 1.6 JRE.
Linux, MacOS X
TeamCity<version number>.tar.gz
Package bundled with Tomcat servlet container for Linux, MacOS X or manual installation.
J2EE container
TeamCity<version number>.war
Package for installation into an existing J2EE container.
Though, the TeamCity server in .exe and .tar.gz distributions is installed with a default build agent that runs on the same machine as the server, this setup may result in degraded TeamCity web UI performance and if your builds are CPU-intensive, it is recommended to install the build agent on separate machines or ensure there is enough CPU/memory/disk throughput on the server machine.
To setup additional build agents follow the instructions.