[complexity] In computational complexity theory, NL (Nondeterministic Logarithmic-space) is the complexity class containing decision problems which can be solved by a nondeterministic Turing machine using a logarithmic amount of memory space. NL is a generalization of L, the class for logspace problems on a deterministic Turing machine. Sin... Found on http://en.wikipedia.org/wiki/NL_(complexity)
[Unix] nl is a Unix utility for numbering lines, either from a file or from standard input, reproducing output on standard output. It has a number of switches: The default applied switch is t. nl also supports a number of command line options. ... Found on http://en.wikipedia.org/wiki/Nl_(Unix)
[format] nl is a file format for presenting and archiving mathematical programming problems. It supports linear and nonlinear optimization problems, complementarity problems (MPECs), in discrete or continuous variables, constraint programming and other types of problems. Initially this format has been invented for connecting solvers to AMPL... Found on http://en.wikipedia.org/wiki/Nl_(format)