An octave may refer to any of the following:
1. Octave, also known as GNU Octave, is a high-level interpreted programming language for performing numerical analysis. It is part of the GNU project and was first released in 1988 with updated versions released as recently as 2014. Octave is a free, open-source alternative to the commercial software MATLAB and is largely compatible with MATLAB's programming language.
2. OCTAVE, also known as operationally critical threat, asset, and vulnerability evaluation, is a set of techniques for risk assessment in the field of information security. It was developed at Carnegie Mellon University in 2001 for the U.S. Department of Defense.