This is a set of ASIC design tools developed by Atmel and others. They were previously used as in-house tools as well as being offered commercially, but are now released under LGPL. Besides the Layout Module Generator Environment MGEN, it also includes the PARIS layout editor and accompanying utilities such as the hierarchical comparison tool LAYDI and the boolean operation server MERGED (released to use with GPL by AISS, now PDF-Solutions).

The kernel of the MGEN system consists of a library containing a set of fundamental functions for creation and manipulation of geometric objects and cells. Based on these functions is a set of higher level functions for the synthesis of more complex structures. MGEN programs can communicate with other tools in different standard interface formats.

PARIS is a technology-independent hierarchical layout editor which can make use of the MGEN functions, and supports both full-custom and cell-oriented IC design. It includes a (Korn-shell-derived) command language.

Update
Now also includes MANIAC, a very flexible graphic viewer for numerical data (e.g. from SPICE or commercial simulators) as well as many (mostly internal) improvements and bug fixes.