| I'm the developer of PikoPixel, a cross-platform Mac/Linux/BSD pixel-art editor. PikoPixel was initially written for Mac, and GNUstep saved me a huge amount of work from having to completely rewrite it for Linux/BSD. However, it was still a significant effort: * GNUstep's an implementation of the Cocoa framework only, it doesn't include any other macOS frameworks. * The same source-code & UI resources can produce different behaviors & visuals between the different platforms. This is due to different Cocoa implementations, some missing functionality on GNUstep, different system fonts, different window managers & desktop environments (Linux/BSD have many of them, each with their own quirks), etc. A cross-platform Mac/GNUstep app is definitely doable - PikoPixel is now available in many Linux distro repositories (Ubuntu Studio even preinstalls it as a default graphics app) - but expect to spend significant effort correcting platform differences (depending on the app). I'd suggest getting started by spinning up a VM, installing a GNUstep dev environment on it, then downloading some GNUstep app sources & building them. PikoPixel's homepage links some build scripts for Debian & Fedora that will install both a GNUstep dev environment and PikoPixel:
https://twilightedge.com/mac/pikopixel/ You can also browse PikoPixel's sources online at the Debian GNUstep team's mirror repository:
https://salsa.debian.org/gnustep-team/pikopixel.app (Note: PikoPixel's fixes & workarounds for the platform differences on GNUstep are found in the various source files that begin with PPGNUstepGlue*). |
This alone would be a nice standalone open source project that one could extend to offer more coverage.