K is a rewrite-based executable semantic framework in which programming languages, type systems and formal analysis tools can be defined using configurations and rules. Configurations organize the state in units called cells, which are labeled and can be nested. K rewrite rules make it explicit which parts of the term are read-only, write-only, read-write, or unused. This makes K suitable for defining truly concurrent languages even in the presence of sharing. Computations are represented as syntactic extensions of the original language abstract syntax, using a nested list structure which sequentializes computational tasks, such as program fragments. Computations are like any other terms in a rewriting environment: they can be matched, moved from one place to another, modified, or deleted. This makes K suitable for defining control-intensive features such as abrupt termination, exceptions, or call/cc.


K Tool Download

  • The provided K Tool Binaries are supported on Linux, OS X, and Windows. Other platforms may or may not work correctly. We welcome information about usability of unsupported platforms or bugs in the supported platforms.
  • Try our Editor Support page for links to K syntax highlighting definitions for various popular editors/IDEs. Please feel free to contribute.
  • The source code (Java) is available on GitHub, where you can also report bugs (please do so).

Learn K

  • K webpage at UAIC (Romania).
  • Matching logic webpage at UIUC (USA).
  • Online K Discussion Channel for K users (Slack & Riot). This is the recommended way to ask questions about K and interact with the K community.
  • Stackoverflow for general questions to the K user community (use the channel above if you want quick answers).