OS X Mavericks is unsupported as of September 2016 and the last released update is OS X Mavericks 10.9.5. iTunes is no longer being updated, but does have partial support for newer devices.

OS X Mavericks can run on any Mac that can run OS X Mountain Lion; as with Mountain Lion, 2 GB of RAM, 8 GB of available storage, and Mac OS X 10.6.8 (Snow Leopard) or later are required.

Mavericks and later versions are all available for free.

The full list of compatible models:

The OS X Mavericks 10.9.5 update is recommended for all Mavericks users. It improves the stability, compatibility, and security of your Mac.

This update includes:

• Improves the reliability of VPN connections that use USB smart cards for authentication
• Improves the reliability of accessing files located on an SMB server
• Includes Safari 7.0.6

For detailed information about the security content of this update, please visit: http://support.apple.com/kb/HT1222

Download OS X Mavericks 10.9.5 Combo Update

File Size: 982.3 MB

Source: apple.com