gridgen is a C code that provides a command line utility for non-interactive generation of multi-corner quasi-orthogonal grids inside simply connected polygonal regions.It is based on the CRDT algorithm that makes it possible to handle regions with elongated channels in a numerically robust way.

Here are example grids from the gridgen package. You can also find a number of grids generated with gridgen for operational estuarine, coastal and regional models at the project's Downloads page.

Checkout gridgen by running "svn checkout https://gridgen-c.googlecode.com/svn/gridgen".

Remember that gridgen is only a tool, and one needs quite a bit of skill to generate a particular grid. It used to take up to two weeks for me to generate a grid for an operational coastal or estuarine model (including testing a few candidates for stability and performance), but it is worth it.

If you are using gridgen you may also need gridutils to work with the grids it produces.

There are a number of front-ends to gridgen. Octant by Rob Hetland is a python suite that provides interactive grid generation for ROMS and GETM.

README