A MetaPost package providing facilities to assist in drawing
diagrams that consist of boxes, lines, and annotations.
Particular support is provided for creating EXPRESS-G diagrams,
for example IDEF1X, OMT, Shlaer-Mellor, and NIAM diagrams. The
package may also be used to create UML and most other Box-Line-
Annotation charts, but not Gantt charts directly.

Homepage:
https://ctan.org/pkg/expressg
