Fontra vs TypeTool 3

Fontra is a free, open-source browser-based font editor designed around variable fonts. It was initially developed to make designing and producing large CJK fonts more efficient. Its architecture combines a JavaScript browser client and Python server, which can run locally or remotely. Fontra Pak bundles the application for desktop use and local file editing; a remote server setup allows real-time collaboration among users, with changes propagating across windows. The project supports reading and writing Designspace and UFO files, as well as reading and exporting TTF and OTF files, including variable fonts. Editing features include live text entry, designspace axis navigation, interpolation, OpenType features, outline editing, components, anchors, guidelines, background images, transformations, kerning, font metadata and variation-axis mapping. Fontra Pak has binaries for macOS 11 and newer, Windows 10 and newer, and Ubuntu x86_64. Linux users can also use Flatpak or Snap; source compilation is listed for other architectures such as ARM or PPC. The repository is licensed under GPL-3.0.

TypeTool 3 has no write-up on Specifiction yet; its figures are above.