Making and hosting a web application just got a whole lot easier. Y Combinator’s AppJet has just launched a website where you can write and run hosted applications right in your browser. The system is currently pretty basic, but aims to add levels of sophistication in the coming year.
Using AppJet reminds me a lot of when I first learned programming through Lisp. Lisp has a simple syntax and processes your code on the fly, making it easy to modify and test code immediately. AppJet is similarly straight forward. Applications are programmed on a web based text editor in the very simple Javascript programming language. Javascript is used on both the server and client side. They’ve included several bundles of code libraries for databases and more importantly interfacing with the Facebook API.
To get your own application, all you have to do is type up your code and save. The application is then published to a unique URL (ex. hello-world.appjet.com) where it runs when anyone goes to the site. Other users can also view an application’s source code to learn and improve upon the original. I’ve embedded an example “message wall” application below.
Hosting other people’s code is tough business. Doing it efficiently requires a system that can dynamically allocate more or less computing resources to programs in response to demand, as well as security that effectively handles maliciously or foolishly programed code. You don’t want an infinite loop taking down the whole system.
To tackle these problems, AppJet has developed their own application virtualization system. The system allocates processor time to active apps and cuts off greedy applications after running an alloted number of compiled lines of code to pevent abuse. While the entire system is currently free, limitations on processing and storage space (10mb), leave an opportunity for paid plans.