Nuke comes in four distinct flavors with different levels of functionality:
• Nuke - The Foundry’s original, award-winning compositing tool. Nuke provides a stable foundation from which to deliver shot-based VFX work.
• NukeX - includes all of Nuke’s features with the addition of a range of specialized plug-in tools to eliminate the need to perform certain tasks in third-party software packages. NukeX is the most powerful application in the Nuke product family. To run it, you need both a Nuke and a NukeX license.
See About NukeX and the NukeX section in the Nuke User Guide for more information.
• Nuke Assist - a feature of NukeX intended for use as a workstation for artists performing painting, rotoscoping, and tracking. Two complementary licenses of Nuke Assist are included in every Nuke X maintenance package. Nuke Assist only supports a limited subset of Nuke tools.
See About Nuke Assist for a run down of the functionality provided by Nuke Assist.
• Nuke PLE - a special version of the commercial Nuke application that you can run without a license, intended for use as an educational tool.
See About the Personal Learning Edition for a run down of the restrictions placed on using the PLE version.