Having worked with both Xilinx & Intel/Altera recently, I can agree that Xilinx works quite nicely.
But Altera works equally well and feels much more natural to me!
Their entire toolchain is very unix-like, which can be seen from an example Makefile like [1] and I had no problems until now to move projects etc. from Windows to Linux and back.
Whereas for Xilinx there have to exist tools like [2] or [3] to be able to build your project on the console and I won't start with the problems I've had with moving projects around or the Xilinx Platform Cable under Linux which ended up in me doing only remote ILA'ing via a Windows box (at least that works w/o a problem).
Unfortunately since Intel bought Altera it seems that they are pulling more and more out of the normal FPGA market, which can make it harder to get support.
Regarding the free tooling, Altera also provides a "Quartus Lite" version which brings you basically the same feature-set than the Xilinx WebPack, for the Altera world.
The Altera toolchain is unfortunately harder bound to SuSe or Redhat than the one of Xilinx.
I haven't worked with lattice yet, but e.g. [4] looks super promising and their toolchain is said to be very linux friendly as well.
Xilinx's tool suite works quite nicely on Linux, and there are excellent "starter kit" FPGAs from some of their partners. I have nothing but good things to say about the Arty line of boards from Digilent (I own one or more of each of them). As you start to approach the higher end of things with larger designs, the boards from Xilinx begin to become your best option unless you've got connections. Note that for small-ish designs the Artix 200 has a reasonable amount of space, and you can simulate and implement for anything up to the Kintex UltraScale+ 5 (including things that don't actually fit in the 5, for simulation) using the same free-as-in-beer WebPack license.
TinyFPGA BX is pretty good (all open source tooling), but generally everyone has linux tools.
edit: unless you meant which one would boot linux best :P Answer is "the expensive ones"
For simulation and formal verification, yes, absolutely. Either Icarus Verilog, Verilator or SymbiYosys have been used for large commercial designs.
For synthesis, the only FPGAs families currently supported by an open source flow are the Lattice iCE40 and ECP5 [0]. The latter is something you can be decently productive with and can fit quite a bit of logic (think: Amiga reimplementation, PCIe interfacing, etc.).
If you'd like to port synthesizeable code from the open source world to the commercial world, this _should_ just work as long as you're willing to rewrite any physical interfacing code (since those depend on hardware blocks available in a particular family) and stick to high-quality Verilog. But that's the same as porting across any other FPGA families.
Disclaimer: I work with SymbioticEDA, who develop and provide commercial support for some open source digital logic tooling, like Yosys and Nextpnr.
