Kaffe is a free software VM and development environment for programs written in the Java programming language. As an independent implementation, it was written from scratch and is free from all third-party royalties and license restrictions. It comes with GNU Classpath core class libraries, and a highly-configurable virtual machine with a just-in-time compiler for enhanced performance.

Kaffe is a clean room design of a Java Virtual Machine. It comes with a subset of the Java 2 Platform, Standard Edition Java API and tools needed to provide a Java runtime environment. Like most other Free Java virtual machines, Kaffe uses GNU Classpath as its class library.

Kaffe is a Bulgarian jazz band who represented their home country in the 2005 Eurovision Song Contest. The group, who sung the song "Lorraine", finished 19th in the semi final.