Lattice has since added a note about free licenses for "hobbyists, enthusiasts, community educators & start-up companies." See the Licensing section at the bottom of this page.
It appears that Lattice Semiconductors, the manufacture of the FPGA used in the Cu, has decided to pull a fast one and silently change the license required to use iCEcube2 from free to an expensive subscription.
It's unclear when exactly this change happened, but looking at the latest snapshot from the wayback machine on February 24th, 2024, it was still free.
On the live site iCEcube2 is now only listed as Subscription for all FPGA families it supports.
Heading over to their online store, I'm currently seeing pricing of $471.31 for the first year and $353.15 to renew each additional year.
This is insane!
iCEcube2 hasn't had any meaningful software updates in many many years. Just take a look at the versions.
The only thing that makes sense to me is that they very much do not want you to use it.
Contact Lattice
If this change bothers you as much as it does me, I highly encourage you to contact Lattice and let them know what you think. Click here for their general inquiries email.
I've sent them an email asking what's going on and I'll update this post if/when they respond.
A Beacon of Hope
Luckily, we have an alternative, Project IceStorm and Yosys more generally.
The open source tools for FPGAs have continued to improve and my latest experiences with them for the Alchitry Cu have been excellent.
Alchitry Labs V2 comes with all the necessary open source tools bundled to work with the Cu without having to compile/install anything else.