OpenLane is an Open Source ASIC tool. You can download it from here. The installation instructions are pretty straight forwards and it takes about 15 minutes and 3GB of disk space.

For a lot of great information on how it works and what it does, please watch Mohamed Shalan’s OpenLane FOSSI dialup presentation

Here’s the overview:

We put our HDL in at one end, and out the other comes the GDS2 files that are the standard file format for the foundry.

The most fundamental steps are:

• Synthesis
• Floor planning
• Place and Route
• sign off: Layout vs Schematic, Design Rule Check, Static Timing Analysis