The package is a specialized tool built on top of PGF/TikZ for drawing spectral sequences. It provides a powerful, concise syntax for specifying the data of a spectral sequence, and then allows the user to print various pages of spectral sequences, automatically choosing which subset of the classes, differentials, and structure lines to display on each page. It also handles most of the details of the layout. At the same time, it is extremely flexible. spectralsequences is closely integrated with TikZ to ensure that users can take advantage of as much as possible of its expressive power. It is possible to turn off most of the automated layout features and draw replacements using TikZ commands. The package also provides a carefully designed error reporting system intended to ensure that it is as clear as possible what is going wrong.