In the early 1980s, Tim King joined MetaComCo from the University of Bath, bringing with him some rights to the TRIPOS operating system.
[3] MetaComCo secured a contract from Commodore to work on AmigaOS, with the AmigaDOS component being derived from TRIPOS.
In 1986, King left MetaComCo to found Perihelion Software, and began development of a parallel operating system, initially targeted at the INMOS Transputer series of processors.
Helios extended TRIPOS' use of a light-weight message passing architecture to networked parallel machines.
Helios 1.0 was the first commercial release in the summer of 1988, followed by version 1.1 in autumn 1989, 1.1a in early 1990, 1.2 in December 1990 followed by 1.2.1 and 1.2.2 updates.
Later Tim King and Nick Garnett gave permission to release the sources under the GNU General Public License v3.
The Helios kernel is effectively a microkernel, providing a minimal abstraction above the hardware with most services implemented as non-privileged server processes.
Once the kernel is loaded, these processes are bootstrapped, and they integrate the newly running node into the Helios network.
The POSIX library assists in porting existing Unix software, and provides a familiar environment for programmers.
It is compatible with products from various manufacturers including INMOS' TRAM systems, the Meiko CS, Parsytec MultiCluster and SuperCluster, and the Telmat T.Node.
Helios can run on T4xx and T8xx, 32-bit Transputers (but not the T2xx 16-bit models) and includes device drivers for various SCSI, Ethernet and graphics hardware from Inmos, Transtech, and others.
In its later versions, Helios was ported to the TI TMS320C40 DSP and to the ARM architecture,[6] the latter used by the Active Book tablet device.