justlazy.js 
Lightweight javascript plugin to lazy load responsive images. Most of the existing javascript plugins using extensive dependencies or supporting just the img-tag without responsive parts. This plugin is supposed to be an alternative.
>> View history and migration path
- 100% performance with plain javascript (no jQuery)
- 100% valid HTML (no empty src tag)
- Simplicity and lightness (just lazy loading of images, no special cases)
- Heavily tested on various devices, browsers and OS versions
Installation
file include
You can download the latest release and include
the justlazy.js file as follows in your page:
<script src="javascript/justlazy.js" type="text/javascript"></script>
If you want to use the lazy spinner, following css file is needed:
<link href="stylesheets/justlazy.css" type="text/css" rel="stylesheet">
npm
$ npm install justlazy
Contributing
Just feel free to contribute..
Project setup
To set up the project you need the grunt-cli:
$ sudo npm install -g grunt-cli
Then you just have to clone the repository and run the install command:
$ npm install
Testing
To run tests manually you can use the $ grunt command to perform jshint and jasmine tests with phantomjs.
Furthermore you can run $ grunt server to call the jasmine runner in your browser localhost:9999
Continuous Integration
justlazy has CI set up through Travis CI and Sauce Labs (free for open-source projects).
Pull-request and checkins will be tested automatically.