Scratch
From APIDesign
From the currently available ways to tech kids programming I consider MIT's Scratch one of the most friendlies. I like the coding style of moving blocks of code - it reminds me of kopenograms - we used them when coding in Karel programming language (I'd still prefer to teach kids Karel as it is simpler and gets to the point, but after recent events I can live with Scratch).
Another beautiful thing is inherent Scratch's support for parallelism and actor based programming model. This is a great contribution to the future - these skills will be needed more and more.
Cloud IDE for Kids
I liked Scratch since the time one could download it or install in as a Linux distribution package. But now it is just brilliant! Just point your browser to
choose from many available projects. Play with them, inspect the source code and if you think your work is good enough: Fork and save it! That is amazing. I can't envision better way to start programming than modifying existing games, learning from their code, turning them into their own versions and publishing them. Here is the game my son improved over last weekend: http://scratch.mit.edu/projects/14887135/