A simple curated list of useful/great open source software projects. Alphabetical sorted. Not more that 5 pojects for each category.
- Godot Engine - An Unity like open source multi platform 2D/3D engine
- Audacity - A popular cross-platform audio software for multi-track recording and editing.
- Hitachi Vantara - A business intelligence, data integration and reporting platform, formely known as Pentaho
- KNIME - A popular open source data analytics, reporting and integration platform
- Orange - An open source data visualization, machine learning and data mining toolkit
- spagobi - An open source Business Intelligence suite
- widestage - A Business Intelligence and reporting tool for mongodb, postgresql, Mysql, MS sql, oracle, & google bigQuery
- mantisBT - A lightweight issue tracker based on PHP.
- Orangescrum - A flexible project and task management web application based on the CakePHP framework.
- OpenProject - A web based project management plattform
- ProjectLibre - A open source replacement for Microsoft Project
- Redmine - A web-based project management and issue tracking tool written in Ruby on Rails.
- Tuleap - An all in one plattform fo issue tracking, project management, document management, test management and collaboration, based on PHP.
- SuiteCRM - A PHP based CRM, originated as a fork of SougarCRM.
- DBeaver - A multi-platform database tool for MySQL, PostgreSQL, MariaDB, SQLite, Oracle, DB2, SQL Server, Sybase, MS Access, Teradata, Firebird and Derby.
- HeidiSQL - A desktop database administation tool for MySQL, MariaDB, Microsoft SQL and PostgreSQL.
Document Store
- CouchDB - A document-oriented NoSQL database.
- MongoDB - A document-oriented database using JSON-like documents with schemas.
Key-Value
- LevelDB - A key-value storage library from Google.
Relational
- MariaDB - A popular fork of MySQL.
- MySQL - Maybe world's most used open source database server.
- PostgreSQL - An other famous open source database server.
Time Series
- Timescale - A time-series database optimized for fast ingest and complex queries. Engineered up from PostgreSQL.
Wide column store
- Apache Cassandra - A distributed NoSQL database designed to handle large amounts of data across many commodity servers.
- Talend Open Studio for Data Integration - A popular ETL and data integration suite fo Windows, MacOS and Linux.
- Candela - An open-source suite of interoperable web visualization components. Can be used with JavaScript, Python and R.
- Charts.js - HTML5 based JavaScript charts
- D3.js - A JavaScript library for creating HTML, SVG and CSS based visualizations.
- Apache Netbeans - A popular IDE for Java, JavaScript, HTML5, PHP, C/C++ and more. Now an Apache project.
- Eclipse - One of the most popular IDEs for almost all popular progamming langauges.
- MonoDevelop - A cross platform IDE for C#, F# and more.
- Notepad++ - A source code editor and Notepad replacement.
- Visual Studio Code - A free multi platform code editor by Microsoft
- 7-Zip - A popular file archiver for Windows.
- PeaZip - A file archiver for Windows and ReactOS. Supports archiving to 7Z, ARC, BZ2, GZ, PEA, TAR, WIM, and ZIP archives.
- Explorer++ - A file manager for Windows
- WinFile - The Original Windows File Manager (winfile) with enhancements
- GNUCash - A personal and small-business financial-accounting software for Linux, macOS and Windows.
- FileZilla - A graphical cross-platform FTP, FTPS and SFTP client for Windows, Linux and macOS.
- WinSCP - A popular graphical SFTP, SCP and FTP client for Windows.
- QGIS - A cross-platform desktop geographic information system (GIS) for viewing, editing, and analysis of geospatial data.
- Pencil - A simple GUI prototyping and mockup creation tool for Windows.
- Blender - A 3D computer graphics software for creating animated films, visual effects, art, 3D models and video games.
- GIMP - A popular and powerful raster graphics editor for image retouching, editing and free-form drawing.
- Krita - A graphics editor designed primarily for digital painting and animation purposes.
- Paint.Net - A image and photo editing software for Windows.
- Freeplane - A cross-plattform mind mapping tool written in Java.
- Gephi - A visualization and exploration software for all kinds of graphs and networks. For Windows, macOS and Linux.
- LibreOffice - The default open source office suite for Windows, macOS and Linux
- CentOS - A Red Hat Enterprise Linux (RHEL) based Linux distribution for server and enterprise usage.
- ReactOS - A project for creating a open source version of Windows (alpha status).
- Scientific Linux - A Red Hat Enterprise Linux (RHEL) based Linux distribution for scientific facilities.
- KeePass - A light-weight and easy-to-use password manager primarily for Windows.
- Insomnia - An open source cross-platform HTTP and GraphQL client
- Greenshot - An open source screenshot software tool for Windows
- PuTTY - A popular SSH/Telnet Client and terminal emulator for Windows and Unix platforms.
- OpenShot - A video editor for FreeBSD, Linux, macOS and Windows.
- ShotCut - A video editor for FreeBSD, Linux, macOS and Windows.
- OpenVPN - OpenVPN can create secure point-to-point or site-to-site connections in routed or bridged configurations.
- Matomo - A popular open-source web analytics platform. Formely known as Piwik.
- WampServer - A Windows web development environment with Apache2, PHP and MySQL/MariaDB
- XAMPP - A web development environment with apache, PHP, MariaDB and Perl