After bad-mouthing Lattice for dropping support for the USB programming interface to their iCEblink40 demo card, I got down to the business of coding my VFD Driver test board test driver.
For those who are insistent about using open-source code to the exclusion of all commercial products, there is an open-source toolchain for the iCE40 series of FPGA: Project IceStorm. That's really cool. If I was looking for an interesting hobby project this might be one, but I already have way too many irons in the fire as it is. Thus I'm using the Lattice-provided IceCube2 development environment.
IceCube2 is a fairly simple wrapper around your choice of two synthesis tools: the Lattice Synthesis Engine (LSE) and Synopsys Synplify Pro. LSE is part of the basic (free) license, while it appears that Synplify requires an extra-cost license. A "performance limited" version of Aldec Active-HDL is provided for simulation and debugging. Active-HDL is a major player in the Verilog/VHDL simulation market, and even the cripple-ware version appears to be on par with Xilinx Isim.
Normally I'd be saying "But Active-HDL won't run under Linux!" at this point, but I found a listing for it in the WineHQ database that gives it a Platinum rating. For non-geeks that means it appears to run very well under the Windows emulation environment in Linux.
I haven't tried to synthesize anything yet, but I may reconsider whether I want to put a Spartan-6 LX4 or an iCE40-HX4K in my calculator rebuild.