Editing Transputer (section)

== Software ==
Transputers were intended to be programmed using the programming language [[occam (programming language)|occam]], based on the [[communicating sequential processes]] (CSP) [[process calculus]].<ref>
  Borger, & Durdanovic, I. (1996). Correctness of compiling Occam to transputer code. Computer Journal, 39(1), 52–92. https://doi.org/10.1093/comjnl/39.1.52
</ref> The transputer was built to run [[occam (programming language)|Occam]] specifically, more than contemporary [[complex instruction set computer|CISC]] designs were built to run languages like [[Pascal (programming language)|Pascal]] or [[C (programming language)|C]]. Occam supported [[Concurrency (computer science)|concurrency]] and channel-based inter-process or inter-processor communication as a fundamental part of the language. With the parallelism and communications built into the chip and the language interacting with it directly, writing code for things like device controllers became a triviality; even the most basic code could watch the serial ports for I/O, and would automatically sleep when there was no data.

The initial Occam development environment for the transputer was the Inmos D700 ''Transputer Development System'' (TDS). This was an unorthodox integrated development environment incorporating an editor, compiler, linker and (post-mortem) debugger. The TDS was a transputer application written in Occam. The TDS text editor was notable in that it was a [[folding editor]], allowing blocks of code to be hidden and revealed, to make the structure of the code more apparent. Unfortunately, the combination of an unfamiliar programming language and equally unfamiliar development environment did nothing for the early popularity of the transputer. Later, Inmos would release more conventional Occam cross-compilers, the ''Occam 2 Toolsets''.

Implementations of more mainstream programming languages, such as C, [[FORTRAN]], [[Ada (programming language)|Ada]], [[Forth (programming language)|Forth]], and Pascal were also later released by both Inmos and third-party vendors. These usually included language extensions or libraries providing, in a less elegant way, Occam-like concurrency and channel-based communication.

The transputer's lack of support for virtual memory inhibited the porting of mainstream variants of the [[Unix]] operating system, though ports of [[Unix-like]] operating systems (such as [[Minix]] and [[Idris (operating system)|Idris]] from [[Whitesmiths]]) were produced. An advanced Unix-like [[distributed operating system]], [[HeliOS|Helios]], was also designed specifically for multi-transputer systems by [[Perihelion Software]].