Analysis Situs uses a number of open source libraries.
Open CASCADE Technology is used as a primary modeling kernel. It can be downloaded from the official web-site.
VTK is used for visualization. Find out more at www.vtk.org.
Qt is used for user interface. Find out more at www.qt.io.
Eigen is used for linear algebra. Find out more at its official web-site.
Tcl is used as a scripting engine. Find out more at www.tcl.tk.