There are a number of Electric libraries available for free download.
Boise State standard cells.
Students at Boise State University
created a standard cell library.
These cells use the MOSIS Submicron design rules with 3 layers of metal,
suitable for fabrication in On Semiconductor's C5 process.
See their site for more information.
Harvey Mudd standard cells and chip.
Students at Harvey Mudd College
designed a 32-bit MIPS microprocessor
and associated standard cell library.
See their project site
for more information.
MOSIS CMOS 350nm Pads. Designed at Sun Microsystems Laboratories,
these pads have been tested and work properly.
Sun Microsystems Test chip. Designed at Sun Microsystems Laboratories,
has over 1 million transistors and was used to measure on-chip and inter-chip capacitance structures.