Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
Python - Python is a clear and powerful object-oriented programming language, comparable to Perl, Ruby, Scheme, or Java.
vClock - Web based time tools including Alarms, Timers, Stopwatch, and World Clocks. vClock is customizable and has a clean user interface.
Java - A concurrent, class-based, object-oriented, language specifically designed to have as few implementation dependencies as possible
YAPA-2 - YAPA-2 is a minimalistic desktop timer app for Pomodoro Technique users.
Rust - A safe, concurrent, practical language