Rational Environment
First released in 1985, the Rational Environment was an integrated development environment for the Ada programming language, which provided good support for abstraction through strong typing. Its goal was to provide the productivity benefits associated with academic single-user programming environments to teams of developers developing mission-critical applications that could execute on a range of computing platforms.
The Rational Environment was organized around a persistent intermediate representation (DIANA), providing users with syntactic and semantic completion, incremental compilation, and integrated configuration management and version control. To overcome a conflict between strong typing and iterative development that produced recompilation times proportional to system size rather than size-of-change, the Rational Environment supported the definition of subsystems with explicit architectural imports and exports; this mechanism later proved useful in protecting application architectures from inadvertent degradation. The Environment's Command Window mechanism made it easy to directly invoke Ada functions and procedures, which encouraged developer-driven unit testing.
The Rational Environment ran on custom hardware, the Rational R1000, which implemented a high-level architecture optimized for execution of Ada programs in general and the Rational Environment in particular. The horizontally-microprogrammed R1000 provided two independent 64-bit data paths, permitting simultaneous computation and type checking. Memory was organized as a single-level store; a 64-bit virtual address presented to the memory system either immediately returned data, or triggered a page fault handled by the processor's microcode.
The company's name was later changed from "Rational Machines" to Rational to avoid emphasizing this proprietary hardware.
Rational provided code generators and the cross-debuggers for then-popular instruction set architectures such as the VAX, Motorola 68000, and x86; much of this was accomplished through a partnership with Tartan Labs, founded by Bill Wulf to commercialize his work on optimizing code generators semi-automatically produced from architecture descriptions (PQCC).
Read more about this topic: Rational Software
Famous quotes containing the words rational and/or environment:
“What is rational is actual and what is actual is rational. On this conviction the plain man like the philosopher takes his stand, and from it philosophy starts in its study of the universe of mind as well as the universe of nature.”
—Georg Wilhelm Friedrich Hegel (1770–1831)
“For those parents from lower-class and minority communities ... [who] have had minimal experience in negotiating dominant, external institutions or have had negative and hostile contact with social service agencies, their initial approaches to the school are often overwhelming and difficult. Not only does the school feel like an alien environment with incomprehensible norms and structures, but the families often do not feel entitled to make demands or force disagreements.”
—Sara Lawrence Lightfoot (20th century)