ISO Development Environment

This article is about the ISO Development Environment. For the commercial organization named Isode, see Isode Limited.

The ISODE software, originally perhaps intended to be an ISO Development Environment, was an implementation of the OSI upper layer protocols, from transport layer to application layer, which was used in the Internet research community to experiment with implementation and deployment of OSI during the late 1980s and early 1990s.

The ISODE software was initially a public domain open source implementation, lead by Marshall Rose. Following version 6.0, Marshall handed the lead over to Colin Robbins and Julian Onions, who coordinated the 7.0 and 8.0 releases. Version 8.0 was the final public domain release - several companies took this release to build sucessful commercial products including Nexor and the Isode Consortium.

While the ISODE implementation could be configured to use one of several X.25 (CONS) or connectionless lower layer protocols, many ISODE deployments were based on [RFC 1006], the implementation of OSI transport protocol TP0 as a layer atop TCP, in order to use IP-based networks which were becoming increasingly common.

ISODE formed the basis for implementations of X.400 (PP) and X.500 (QUIPU), and the approaches for providing a simplified directory lookup protocol that was easier to implement in a client than X.500's Directory Access Protocol led to the development of the Lightweight Directory Access Protocol.

Implementations of FTAM and VT were included in ISODE, and implementations of X.400 P7 (PPMS), TMN (OSIMIS) and other OSI protocols were also made atop ISODE.