These are tools for CellML model editing and use. They are capable of model creation, editing, simulation, validation, and visualisation.
OpenCell is the result of the merger between PCEnv and COR, using PCEnv as a code base. It is an open source environment being developed at the Auckland Bioengineering Institute. It makes use of the CellML DOM API. OpenCell is built on top of the Mozilla platform. The latest available release was made before the merger; it is PCEnv 0.6.