Inkscape is closely comparable to Adobe Illustrator and features plenty of similar illustrating, sketching, and editing tools.
GNU Image Manipulation Program (GIMP) offers limited vector functions and has similar tools to Photoshop.
There is no single magic bullet solution, but Blender can help fill in some gaps if you don’t run Adobe software.
If you’re searching for an alternative to Adobe Photoshop, Pixlr could be your best bet.
If you’ve ever thought of giving Lightroom a try, RawTherapee could be your perfect bet. You can use this tool to edit Raw photo files and multiple other formats.
BoxySVG runs as a Google Chrome extension, making it easy to store vector graphics, including illustrations, icons, and charts on the web.
DaVinci Resolve is an excellent alternative to Adobe Premiere Pro. This professional video editing tool is so good that professional designers use it on big-budget TV and film productions.