Screen calculator
Physical size in cm, pixel density (PPI), dot pitch and aspect ratio from resolution and diagonal, with saveable screens for comparison.
OpenTools
Small utilities I use myself. Schafkopf and Wizard run directly in the browser; Schafkopf can also open a private online table when you want to play with friends.
All tools
Kartenspiele
Schafkopf and Wizard today, Skat and Doppelkopf next: keep the score offline, play Schafkopf against bots or open a private online table for friends. Full rules reference, German and English.
OpenRegex playground
Build regular expressions from examples and building blocks, test them with live match highlighting, and get every part of the pattern explained in plain English.
Open