This extension.lay possess files that encode information for drawing concepts and a printed plan. In particular, such a file can be useful to someone who develops and creates various electronic cards for a wide range of devices.
Here are a few programs that allow you to work in a comfortable environment with this extension:
SprintLayout 4.0 - a handy utility for drawing boards and their subsequent refinement. There are enough versions on the Internet, including in Russian.
sPlan 5 - this program also worked well in the environment of designers of electronic devices. It has powerful capabilities to create the most high-quality product.