natbib

Natbib is a LaTeX package that extends BibTeX citation support, providing flexible handling for both author-year and numerical citation styles. It offers a set of citation commands that go beyond the basic \cite, enabling more precise formatting and placement of citations in scholarly texts. The core commands are \citet for textual citations (for example, Jones et al. (1990)) and \citep for parenthetical citations (for example, (Jones et al., 1990)). The package also provides auxiliary commands such as \citealp, \citeauthor, and \citeyear to extract specific parts of a citation, as well as forms that allow pre- and post-notes, e.g., \citep[see][]{jon90} or \citet[e.g.,][]{jon90}.

Natbib is designed to work with standard BibTeX bibliography styles, including plainnat, abbrvnat, and unsrtnat, enabling consistent formatting across author-year or numeric modes depending on the chosen style. It is intended for use with BibTeX rather than biblatex and integrates well with hyperref.

Configuration typically involves loading the package with options, for example \usepackage[options]{natbib}. Options control citation formatting, such as numbers to yield numeric citations, square or round to choose bracket shapes, and sorting or compressing of multiple citations (e.g., sort, compress, sort&compress). The package adapts to the selected BibTeX style and provides mechanisms to adjust punctuation and citation layout through its commands.

Limitations and current context: natbib is not compatible with biblatex, which has largely superseded it in modern workflows; however, natbib remains widely used for legacy documents and certain journals. It has a long-standing presence in TeX distributions and is well documented. Historically, natbib was developed and maintained by Patrick W. Daly.