To build jQuery, you need to have the latest Node.js/npm and git 1.7 or later. Earlier versions might work, but are not supported. For Windows, you have to download and install git and Node.js. OS X users should install Homebrew. Once Homebrew is installed, run brew install git to install git, and brew install node to install Node.js. Linux/BSD users should use their appropriate package managers to install git and Node.js, or build from source if you swing that way. Easy-peasy. Special builds can be created that exclude subsets of jQuery functionality. This allows for smaller custom builds when the builder is certain that those parts of jQuery are not being used. For example, an app that only used JSONP for $.ajax() and did not need to calculate offsets or positions of elements could exclude the offset and ajax/xhr modules. Any module may be excluded except for core, and selector. To exclude a module, pass its path relative to the src folder (without the .js extension). Some example modules that can be excluded are: Note: Excluding Sizzle will also exclude all jQuery selector extensions (such as effects/animatedSelector and css/hiddenVisibleSelectors). The build process shows a message for each dependent module it excludes or includes. As an option, you can set the module name for jQuery's AMD definition. By default, it is set to "jquery", which plays nicely with plugins and third-party libraries, but there may be cases where you'd like to change this. Simply set the "amd" option: For questions or requests regarding custom builds, please start a thread on the Developing jQuery Core section of the forum. Due to the combinatorics and custom nature of these builds, they are not regularly tested in jQuery's unit test process. The non-Sizzle selector engine currently does not pass unit tests because it is missing too much essential functionality.