Another thing: I don’t know how the tasks from "tasks/context.json" are supposed to work. They don’t appear under "Run Task" (Ctrl-F12). I made my own tasks.json (doesn’t work in ~/.vscode-oss or ~/.vscode, but only in <project>/.vscode), that works to call context or mtxrun, but it won’t ever open an external PDF viewer. I found a workaround via command substitution (backticks): { // See https://go.microsoft.com/fwlink/?LinkId=733558 // for the documentation about the tasks.json format "version": "2.0.0", "tasks": [ { "label": "ConTeXt", "type": "shell", "command": "context --autopdf=auto '${file}' && `xdg-open '${fileBasenameNoExtension}.pdf'`", "args": [], "options": { "cwd": "${fileDirname}" }, "group": { "kind": "build", "isDefault": true } }, { "label": "check file", "type": "shell", "command": "mtxrun --script check '${file}'", "args": [], "options": { "cwd": "${fileDirname}" }, "group": { "kind": "test", "isDefault": true } }, { "label": "open PDF in external viewer", "type": "shell", "command": "`xdg-open '${fileBasenameNoExtension}.pdf'`", "args": [], "options": { "cwd": "${fileDirname}" }, } ] } Hraban