I very recently updated to Mac OS Sierra, version 10.12.5. I use Gimp to process images and for some of my knit charting. The last version I had installed was stable in the previous OS, but cranky in Sierra. The latest version 2.8.22 download can be found at the developer site. So far it is downloaded by me, but not yet tested. X Quartz, necessary for using Inkscape is still unchanged, release version 2.7.11.
If you have been using Excel for charting, and wish to import files into the latest version of Numbers for any reason, Numbers will open files created in Microsoft Excel – Office Open XML (.xlsx) and Office 97 or later (.xls). To import any spreadsheet file from Finder, right-click on the file, then click “Open with… > Numbers.” If Numbers is the only spreadsheet application on your Mac, you can simply double-click. If you are already in the Numbers for Mac app, choose File > Open, then click on the file you want to work on. If a file is grayed out, it isn’t in an acceptable format. Excel.xlsb files are such an example. Save document again in .xlsx or .xl format for the Numbers import.