2. Clean slate design, applying latest insights concerning cpu design, virtualization & so on.
3. More a community effort & perhaps more open than other ISAs.
OpenSPARC is (unlike early Sparc cpus) targeted at high-performance server / supercomputer chips.
Similar for OpenPOWER which is mostly an IBM affair. And opened only around the time RISC-V came out.
From what I've read (no personal experience), OpenRISC wasn't that well-designed or lacks RISC-Vs modularity.
So a combination of license, community, ISA design & timing of its introduction.
2. Clean slate design, applying latest insights concerning cpu design, virtualization & so on.
3. More a community effort & perhaps more open than other ISAs.
OpenSPARC is (unlike early Sparc cpus) targeted at high-performance server / supercomputer chips.
Similar for OpenPOWER which is mostly an IBM affair. And opened only around the time RISC-V came out.
From what I've read (no personal experience), OpenRISC wasn't that well-designed or lacks RISC-Vs modularity.
So a combination of license, community, ISA design & timing of its introduction.