I learned how to program in C on Lattice. At my first real job, we used the Lattice C compiler for Unix and MS-DOS. I bought the Amiga version and taught myself C with it. Back in the early 80’s, Lattice was the only game in town for getting commercial C compilers. Even Microsoft repackaged it as Microsoft C until they came out with their own compiler (MS C 4.0). By the time I was using it (1988), Lattice was being eclipsed by Microsoft’s own C compiler and Borland’s Turbo C. We eventually dropped it for the Watcom C compiler, a C compiler that ran circles around Microsoft C back then. It’s hard to imagine, but Microsoft used to have serious competition in the compiler area. Watcom C was nearly 100% compatible with Microsoft C at the source level, but it would compiler smaller executable that ran faster than the same code compiled with Microsoft C. Mind you, this was back in the early 90’s and Visual Studio did not exist. Lattice was eventually bought out by the SAS Institute, who then effectively killed it.
I was surprised to see that Watcom C is still around as Open Watcom C/C++ and FORTRAN. Sybase ended up owning Watcom and realized that maintaining the compilers didn’t make a lot of business sense. So they open sourced it about 5 years ago. It looks like you can still build Netware NLM‘s with it. If you ever needed to write a NLM, this would be the way to do it without having to spend any money.