It was designed for numeric and logical computations and was the first language to provide a bootstrap implementation.
It is called a variant of ALGOL 58 because of similarities to that language, but, shortly after the ALGOL committee produced other versions of ALGOL, and NELIAC and ALGOL parted ways.
The decompiler was a curiosity. The first version ran on the Countess, but it was later ported to the CDC 1604 and to other computers and received some notice in University circles. But, it turned out that there were few programs worthy of decompilation available at the time.
NELIAC was never intended to be a commercial product. Its primary advantage over other compilers of the day was its portability to other computers and its one-pass architecture which made possible such rapid compile times that it compiled 60 to 120 times faster than other high level languages. The JOVIAL compiler had 14 passes, for example. The simplicity of the language and its extremely fast compile times permitted much faster development cycles than other contemporaneous compilers. It was an in-house NEL effort to make possible a more cost-effective solution to the problem of computer system development.
NELIAC was used to implement an experimental anti-submarine shipboard system, and was also used for the development of the National Emergency Command Post Afloat (NECPA) project which developed a strategic command and control system installed on aircraft carriers and cruisers. In addition, NEL developed NELOS, a batch operating system which provided input-output for magnetic tapes, printers, and telecom equipment, provided sequenced compiling of jobs, and a symbol library permitting linking of very large computer applications and executing them on-line. These included suites of information management programs, including databases, free form queries with a precursor of IBM's GIS, and reporting applications. NECPA and NELOS went to sea in 1966.
Many other well-known computer experts like Niklaus Wirth made contributions to the project, but ultimately NELIAC fell out of favor after the Navy Department standardized on compilers with commercial support.