Hemlock is integrated with the Common Lisp compiler, interpreter, and development suite CMUCL, though it is possible to use it as a standalone editor, or to use GNU Emacs with CMUCL instead — Hemlock integrates better, but has fewer features and addon programs. One distinctive feature is that Hemlock distinguishes Lisp functions from interactive commands, which are given in a more natural-language-like style derived from the original Lisp machine and TECO Emacs. It is able to display to a terminal, or use the CLX (Common Lisp X Library) for X11.
Hemlock is also the editor of the Clozure CL (formerly OpenMCL) development environment. The editor of LispWorks has been based on Hemlock also.