Does Lattice offer any software that is free?
Lattice is both a hardware and software company, providing the software used to design and program the logic within the Lattice devices. Some of that software is free and some isn't. As you're reading this, you have some interest in the free stuff, so here's a quick list:
Lattice Diamond (best in class design tool for most Lattice devices including SERDES)
Lattice Radiant (next generation design tool for small form factor FPGA application devices)
Lattice Propel (design environment for Lattice FPGA-based processor system design)
iCEube2 (for legacy iCE devices)
Power Calculator (power analysis of Lattice devices in your application)
PAC Designer (design tool for ispPAC devices)
There are also additional tools within the software above that you might not have realized were free. For example, modules in the IPExpress tool (within Diamond and ispLEVER) such as PLL's, DLL's, RAM, SERDES PCS, multipliers and others. Use the IPExpress graphical interface to produce the HDLs automatically for those items. IPExpress provides access to the latest IP cores for purchase as well.
You can download and install the above free software design tools at the Lattice website.
For the Radiant and Diamond software, be sure to scroll down the page and view the table showing what devices and features are available in the various versions. Once the above software is downloaded and installed, there will then be a license request you will send to Lattice, the license is sent back to you, you then copy the license into the proper path on your development system, and you're up and running.
Since the software listed above is free, it's easy to download the latest versions as the software group continuously updates and improves them.