| Intel IA-64(Itanium) | EPIC | Linux, Microsoft Windows, HP-UX, HP NonStop, BSD, Runs Win32 at reduced speed | Launched in 2001, but seen as disappointing. Much improved Itanium 2 ("McKinley") launched in 2002 | Architecture designed to last until 2020. Future dual-cored versions incorporate HP-PA technology |
| AMB x86-64(Opteron, Athlon64) | CISC | Linux now, Windows planned, Runs Win32 at full speed | Opteron launched April 2003, aimed at high-end and mid-range servers | May bring 64-bit computing to the masses when Athlon64 is launched |
| IBM Power | RISC | Linux, IBM AIX, IBM z/OS, IBM VSE | Designed in 1990s for IBM mainframes. Latest dual-core Power4 also used in servers | Power5 due soon. Architecture also incorporated into PowerPC 970 chips for lower-end servers and Apple Macs |
| HP Alpha | RISC | Linux, HP-UX, BSD | Developed by DEC in 1980s. Latest EV-7 still used in high-end servers | New version (EV-9) due in 2004. Then, migrate to Itanium |
| HP Precision Architecture (PA) | RISC | Linux, HP-UX, HP NonStop | Developed by HP in 1990s. Latest dual-core 8800 used in mainframes | New version (8900) due in 2005. Then, migrate to Itanium |
| Sun UltraSPARC | RISC | Sun Solaris, Linux, BSD | Developed in 1990s as proprietary system, UltraSPARC III now open | Dual-core UltraSPARC IV due later in 2003, UltraSPARC V planned |
| Source: NetworkMagazine.com |