Most are no longer available, running on hardware that hasn't been available for years.
Acorn RISCiX
Alliant FX/8 with Concentrix 4.1
Altos 486, 586, or 986 with XENIX 3.0
Altos ACS68000 with Unix System III R2
Amdahl mainframes with UTS 2.4 and UTSV 5.2.6b
Amdahl mainframes with Unix System V R5.2.6
Apollo workstations with Aegis 9.7 and with DomainOS SR10.0 and 10.4
Apple Macintosh with A/UX
Apple Powerbook with MachTen 2.1.1.D
AT 3B2 and 3B20 systems with Unix System V R2
AT 6300 PLUS with Unix System V R2
AT 6386 WGS Unix PC with Unix System V/386 3.2
AT PC 7300 UnixPC (3B1) System V R3.51m
Atari Falcon with MiNT
Atari ST with MINIX ST 1.5
BeBox with BeOS DR7
Bull DPX/2 with BOS/X
Bull Escala and other RS/6000 compatibles with AIX
Charles River Data Systems Universe with UNOS 9.2
Commodore Amiga with Unix System V R4
Commodore Amiga with MINIX 1.5.10
Concurrent (Masscomp) computers with RTU 4.0 through 6.0
Convergent Technologies MiniFrame with CTIX System V R3
Convex C1 and C2 with Convex/OS 8.x and 9.x
Convex 3240, C220, and C240 with ConvexOS V10.x
Cray supercomputers with UNICOS 6.1 through 8.0and with CSOS 1.0
DEC Alpha, DECstation, and or PC with with OSF/1 versions 1 through 3
DEC Alpha with Digital Unix 3.2 through 4.0
DEC Alpha with Linux
DEC PDP-11 with 2.4, 2.9, 2.10, and 2.11 BSD
DEC VAX with 4.1BSD, 4.2BSD, 4.3BSD, 4.3BSD-Reno, 4.3BSD-Networking/2
DEC VAX with ATT Bell Labs Unix 7th Edition
DEC VAX with ATT Bell Labs Research Unix 10th Edition
DEC VAX with ATT System V R3
DEC VAX with ULTRIX 1.0, 2.0, 3.0, and 4.x
DECstation with Berkeley Sprite
DECstation with MACH 2.6
DECstation with ULTRIX 4.2 through 4.5
Data General AViiON 88K with DG/UX 4.3 through 5.4.3
DIAB DS90 with DNIX 5.2 and 5.3
Dolphin Server Technology Triton 88/17 with Dolphin Unix System V/88 R3.2
Encore Multimax with UMAX 4.3
Encore 88K with UMAX V 5.2
Fortune 32:16 with For:Pro 2.1
FPS 500 with FPX 4.1
Harris HCX-2900
Harris Night Hawk 68K and 88K with CX/UX
HP-9000 with 4.4BSD
HP-9000 with HP-UX 5.00 through 10.30
IBM 370-series mainframes with AIX/370 1.2
IBM 370-series mainframes with AIX/ESA 2.1
IBM PS/2 with AIX 1.0 - 1.3
IBM RS/6000 and Power Series with AIX 3.0 through 4.2
IBM RT PC with AIX 2.x, ACIS 4.x, and 4.3BSD-Reno
ICL DRS400 and 400E with System V R3
ICL DRS3000 and DRS6000 with DRS/NX Unix System V R4;
Integrated Solutions VS8 with ISI 4.2BSD
Intel 302 with Bell Tech System V/386 R3.2
Intergraph Clipper with CLIX
Luxor ABC-9000 with DNIX
MIPS Computer Systems with RISC/os UMIPS 4.52
Modcomp Realstar 1000 with Real/IX D.1
Motorola Four Phase
Motorola VME Delta Series with System V/68 R3
Motorola VME Delta Series with System V/88 R32 and R40
NCR Tower 1632 with System V R2
NCR Tower 32 with OS 1.x-2.x
NCR System 3000 and MP-RAS with System V R4
NeXT workstations with NeXTSTEP/Mach 1.0 through 3.3
Nixdorf Targon/31 M15 with TOS 4.0.13
Norsk Data Uniline 88/17 with System V/88 R3.2
OkiStation 7300 Series with System V R4
Olivetti CP 486 with Unix System V R4
Olivetti LSX 3005 through 3045 with X/OS Unix 2.3 through 3.0;
Olivetti LSX 5020 with SCO Unix 3.2.2
PCs with 386BSD (Jolix)
PCs with ATT Unix System V R3.2
PCs with BSDI/386 1.0-2.1
PCs with Dell Unix System V/386 R4.04 issue 2.2
PCs with DG/UX 5.4
PCs with ESIX System V R3 and R4
PCs with FreeBSD 1.0 and 2.0
PCs with Interactive Systems Corporation System III PC/IX
PCs with Interactive Systems Corporation 386/ix 1.x and 2.x
PCs with Interactive Systems Corporation System V/386 R3.2 V2.2-4.0
PCs with Linux
PCs with Lynx/386
PCs with Mark Williams COHERENT/386 4.0 and 4.2
PCs with MINIX/386
PCs with Microport SV/AT System V R2
PCs with Microport 3.0U3 and SVR4.0 V2.2-4.1
PCs with Mt Xinu Mach386
PCs with NetBSD
PCs with NeXTSTEP/486
PCs with QNX 4.0 through 4.23
PCs with SCO ODT 1.1 through 3.0
PCs with SCO Open Server R5.0
PCs with SCO Unix/386 3.2.x
PCs with SCO Xenix/286 2.3.3
PCs with SCO Xenix/386 2.2.x and 2.3.x
PCs with SunSoft Solaris 1.0 through 2.5.1
PCs with Trusted Xenix
PCs with UnixWare 1.0 through 2.1.1
Perkin-Elmer 3200 series with ATT Bell Labs Unix V7
Perkin-Elmer 3200 series with ATT System V R3
Perkin-Elmer 3200 series with Xelos R02
PFU Compact A Series SX/A TISP V10/E50
Plan 9 from Bell Labs on Intel, MIPS, SPARC, and 680x0
Prime EXL7000 or 8000 MIPS RISC/os 4.52
Pyramid MIS T Series with OSx 4.4 through 5.1a
Pyramid MIS S and ES Series with DataCenter/OSx
Sequent Balance or Symmetry with DYNIX 3.x and DYNIX/paratx 1.3, 1.4, and 4.0
Siemens Nixdorf RM 200 with SINIX 4.52
Siemens PC-X with SINIX (Intel 80186 cpu)
Siemens PC-MX with SINIX (Intel 8086 cpu)
Siemens PC-MX2 and 4 with SINIX (National Semiconductor 32016)
Siemens PRIMEPOWER with Solaris 8 (SPARC64).
Silicon Graphics IRIX 3.3 through 6.2
SINIX on IA-32 platforms
Solbourne 5E/900 with OS/MP 4.1A
Sony NEWS with NEWS-OS 4.x
Sperry 5000 with UTS V and System V R3
Stardent 1520 Unix System V R3 2.2
Stratus computers with FTX 2.x
Sun computers with Plan 9 from Bell Labs
Sun computers with NeXTSTEP 3.3
Sun computers with SunOS 3.2 through 4.1.3
Sun computers with Solaris 1.0 through 2.5.1
Tandy Model 6000 with XENIX 3.2
Tektronix 6130 with UTek OS
UNISYS 640 with CTIX SVR3.2 5.3
UNISYS S/4040 with CTIX SVR3.2
UNISYS U6000/65 MP with Unix System V R4