Algorithm Visualizer - Write down your algorithm to be visualized
CSS Grid Garden - A game for learning CSS grid layout
Algorithmia - Algorithmia makes applications smarter, by building a community around algorithm development, where state of the art algorithms are always live and accessible to anyone.
Quantiacs - Earn money by creating trading algorithms in your spare time
The Algorithm Design Manual - Learn about designing and analyzing algorithms
Grokking Algorithms - An illustrated guide for programmers & other curious people