PSPP is a free software application for analysis of sampled data, intended as a free alternative for IBM SPSS Statistics.

Cacti is a network graphing solution designed to harness the power of RRDTool's data storage and graphing functionality.

LibreNMS is an auto-discovering PHP/MySQL-based network monitoring system.

Observium is a low-maintenance auto-discovering network monitoring platform supporting a wide range of device types, platforms and operating systems, etc.

GraphCalc is an open source software for Windows and Linux that provides the functionality of a graphing calculator.

Origin is the data analysis and graphing software.