OS X Mavericks is free, but Mavericks Server still costs you - but it's only $19.99. Apple released OS X Server late Tuesday after posting Mavericks to the Mac App Store.
OS Server works like an application, running on top of the core Mavericks operating system. All the hallmarks of OS X Server are still apparent in the new Mavericks release: server-strength file sharing, e-mail service, contact, calendar and database publishing, support for PostgreSQL for SQL databases, Apache web server, and much more.
New to Mavericks Server includes Xcode Server, making it easier to use OS X Server in developer workgroup settings (for both iOS and OS X developers), a new Caching Server 2 that speeds up the delivery of software distributed over Mavericks Server from the App Store, Mac App Store and iTunes. Profile Manager gets some enhancements too, to simplify the delivery of apps and books.
Are you planning to install Mavericks Server? Are you working with Mountain Lion Server now? IT pros, sound off in our comments!