Mac OS X Server v10.5: Choose either 10-client or unlimited client
The Apple Maintenance Program (AMP) provides your organization with the most up-to-the-minute advances of the Mac OS X Server operating system over time - at a significantly reduced price.
In a nutshell, the Apple Maintenance Program enables organizations like yours to subscribe to software upgrades instead of purchasing them each time they are released, and to benefit from substantial savings over time.
A three-year, non-cancelable agreement that entitles your organization to receive every major upgrade release to Mac OS X Server, the Apple Maintenance Program is designed to protect your software investment and reduce your total cost of ownership. The program's affordable one-time fee simplifies budget management, reduces your administrative overhead, and puts a lid on IT maintenance and software distribution costs. Upgrades are shipped automatically, so all of your computers can be standardized with the latest server software. And, naturally, the more servers you've licensed, the more you'll save.
Apple Maintenance
The Apple Volume License and Mac OS X Maintenance Program is a GET CURRENT - STAY CURRENT program. First, purchase your Mac OS X upgrade Volume License and second, enroll in Maintenance to receive Mac OS X upgrades for a three year period.