RandR is X11 extension for configuring monitors and since version 1.4 also secondary GPUs. These secondary GPUs can either provide additional monitors to output to or can render individual applications instead of the main GPU. (Or even both at once.) Once a secondary GPU is configured to do render offloading, applications can be started with DRI_PRIME=<id> environment variable to actually render on it instead of the main one. There are also USB GPUs (dummy framebuffers) that can be hot-plugged.
VNC protocol transfers key symbols (= basically characters), not key codes (= "coordinates" on keyboard). Therefore pressing the same keys may result in sending different commands over VNC depending on the keyboard layout and state of modifiers on the client side. The server however can not directly send the key symbol to the application, it must instead find or create key code that will translate to that symbol and send that.
This is hard to implement correctly and there was already several bugs about it.
Tigervnc comes with two very similar VNC viewers - one written in C++ and one in java. The java one can be embedded in a webpage as a java applet. We use that in our default VNC setup (the one enabled in YaST). That way if user doesn't have VNC viewer installed, browser is enough.
However running java applets in browser is getting harder every day. Especially when the applet isn't signed by a trusted authority.
This is preparation/accompanying project to my school thesis.
Fontconfig is library that keeps database of fonts installed in system and gives applications ability to query it. Fontconfig is currently searching the database in naive way and can be quite slow if there is many fonts installed. Most applications make several font queries when starting and fontconfig is slowing down their start.
I use the KDevelop IDE whenever I can. At SUSE mostly for reading code while debugging some bug. My plan is to create plugin that will show extra information inline with the code to make it easier to explore foreign code.
Examples include showing names of function parameters at call site, elided types of variables (e.g. C++ auto, lambda parameters), comments next to closing brackets etc.