AsgardJS is a less-than-1K (1015 bytes) microframework to make routine HTML5 tasks easier. It includes DOM manipulation, client-side URL hash routing, a basic string templating engine and AJAX calls. Use with HTML5 doctype only!
P.S. Please keep in mind AsgardJS is oriented for the modern Web, so neither it does include some things that are already implemented as native browser solutions (e.g. it has no class manipulation because there's no need to reinvent classList), nor it has any obsolete browser support. Estimated support for browser versions: Chrome 5+, IE 10+ (9 may work), Firefox 4+, Opera 12+, Safari 5+, Android Browser 2.2+. DOM manipulation
Element._(selector)- check if the element matches the selector