LiveCode is both an open-source and proprietary cross-platform rapid application development language.
Ranked in these QuestionsQuestion Ranking
Pro Approachable yet capable language
Pro Extremely simple to get started
Single-click install of entire development environment, and all-in-one IDE makes it easy to go from visually layout out a user interface to writing code to power it to creating your own single-file applications.
Pro Fast to get results
Inside LiveCode's IDE you can build for OSX, Linux and Windows, and (making use of Xcode and the Android SDK) for iOS and Android too
Pro GUI-driven development
In LiveCode, you start by dropping GUI elements into place, then add the code that makes them function. This lets beginners see visual results right away, which is often more exciting (especially for young students). It also lets you focus on the user interaction before you get into the nitty-gritty of code implementation.
Con Poor Ecosystem
Not a mainstream programming language.