CHILL is the acronym for CCITT High Level Language (where CCITT stands for Consultative Committee for International Telephony and Telegraphy, now ITU-T (ITU Telecommunication Standardization Sector)).
The latest language specification Z.200 provided by ITU-T can be found at https://www.itu.int/rec/T-REC-Z.200/en ([1]).
The language had been devised in the 1970s, with focus on structured and modular programming (visibility of variables, abstract and generic data types, separate compilation units) and concurrent processes.
At the same time the American Department of Defense (DoD) has initiated the development of the programming language Ada.
Similar requirements resulted in CHILL and Ada being very close in design, features and complexity, [2] elaborates on the rivalry between the two languages.
The language's main field of employment was with digital telecommunication switching systems ([6], the eminent role that CHILL had in that field might be compared to that of Ada in avionics today).
Several compilers had been developed in the 1980's by telecommunication companies, e.g. Siemens ([4]), Philips ([5]).
The GCC toolchain provided with version 2.95 (with several releases between July 1999 and March 2001) a CHILL compiler. Later GCC releases had CHILL removed due to a lack of interest.
GCC CHILL has been distributed as a 32-bit compiler. It implements most parts of the 1988 ITU standard.
To get started with CHILL download the following:
the CHILL executable cc1chill
the source code for libchill.a libchill.tar.gz
CHILL source code samples code.tar.gz
To run the compiler the directory containing the cc1chill executable must be in the PATH environment variable.
For convenience and for demonstration purposes the directory with source samples already contains the libchill.a library so the linker statement in the Makefile just adds "-lchill -L." to the gcc linker line.
libchill.a can be placed anywhere you like, in addition you might build libchill.a from the provided source code directory.
[1] https://www.itu.int/rec/T-REC-Z.200/en provides the latest Z.200 specification.
[2] G. Paulsen: Betwixt and between. Software in telecommunications and the programming language Chill, 1974 - 1999 (https://biopen.bi.no/bi-xmlui/bitstream/handle/11250/94362/2011-08-Paulsen.pdf)
[3] a chapter (page 70) in https://www.telenor.com/wp-content/uploads/2012/05/T00_4.pdf or http://psc.informatik.uni-jena.de/publ/2000-CHILL-2000-jfhw.pdf
[4] W. Sammer, H. Schwärtzel: CHILL. Eine moderne Programmiersprache für die Systemtechnik. (Springer, 1982)
[5] J. Lenzer, T. Letschert, A. Lingen, D. Hollis: Eine Einführung in die Programmiersprache CHILL. (Hüthig, 1987)
[6] (p. 5-10) https://www.telenor.com/wp-content/uploads/2012/05/T93_2-3.pdf
[7] An introductory text from Brazil: Introduction to CHILL.