Gabedit is a Graphical User Interface to Gamess-US, Gaussian, Molcas,
Molpro and MPQC computational chemistry packages. Gabedit includes
graphical facilities for generating keywords and options, molecule
specifications and their input sections for even the most advanced
calculation types. Gabedit includes an advanced Molecule Builder. You
can use it to rapidly sketch in molecules and examine them in three
dimensions. You can build molecules by atom, ring, group, amino acid and
nucleoside. You can also read geometry from a file. Most major molecular
file formats are supported.