Abc-Map is a free and open source mapping software. With Abc-Map you can easily create, edit and visualize geospatial information. You can export maps to PDF or share them online and even embed them in your websites. Abc-Map works on all platforms with a web browser (Linux, Mac OSX, Android, IOS, Windows). (GPL)
Cross-platform
Reactive Resume is a free and open source resume builder that’s built to make the mundane tasks of creating, updating and sharing your resume as easy as 1, 2, 3. With this app, you can create multiple resumes, share them with recruiters through a unique link and print as PDF, all for free, no advertisements, without losing the integrity and privacy of your data. (MIT)
Cross-platform
Syncthing is a continuous file synchronization program. It synchronizes files between two or more computers in real time, safely protected from prying eyes. Your data is your data alone and you deserve to choose where it is stored, whether it is shared with some third party, and how it's transmitted over the internet. (MPL)
Linux - Windows - MAC OS X - FreeBSD
Subtitld is probably the best open source software to edit, transcribe and create subtitles. It is able to read SRT, SSA, TTML, SBV, DFXP, VTT, XML, SCC and SAMI file formats and to write SRT file format by default. (GPL)
Linux - Windows
VPaint is an experimental vector graphics editor based on the Vector Animation Complex (VAC), a technology developed by a collaboration of researchers at Inria and the University of British Columbia. (MIT)
MAC OS X - Windows - MAC OS X
Dotgrid is a grid-based vector drawing software designed to create logos, icons and type. It supports layers, the full SVG specs and additional effects such as mirroring and radial drawing. Dotgrid exports to both PNG and SVG files. (MIT)
Linux - Windows - MAC OS X
SonoBus is an easy to use application for streaming high-quality, low-latency peer-to-peer audio between devices over the internet or a local network. Simply choose a unique group name, and instantly connect multiple people together to make music, remote sessions, podcasts, etc. Easily record the audio from everyone, as well as playback any audio content to the whole group. (GPL)
Linux - Windows - MAC OS X
Veloren is a multiplayer voxel RPG written in Rust. It is inspired by games such as Cube World, Legend of Zelda: Breath of the Wild, Dwarf Fortress and Minecraft (GPL)
Linux - Windows - MAC OS X
Enve is a new open-source 2D animation software for Linux and Windows. You can use enve to create vector animations, raster animations, and even use sound and video files. Enve was created with flexibility and expandability in mind. (GPL)
Linux - Windows
Organize your daily tasks in one place while making time tracking a lot less annoying. Super Productivity is a ToDo List / Time Tracker / Personal Jira Task Manager for Linux, MacOS and Windows aimed at reducing the time you spend with repetitive tasks and to provide you with a place to collect all the information you need to do your job. (MIT)
Linux - Windows - MAC OS X