quartus-prime-lite : Full-featured EDA product for altera devices ( https://www.altera.com/products/design-software/fpga-design/quartus-prime/overview.html )
verilator : The fastest free Verilog HDL simulator ( https://www.veripool.org/wiki/verilator )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a panther
For Paludis use this rsync : rsync://gentoo.zugaina.org/panther-portage
If you have a problem : ycarus(-at-)zugaina.org