DomBuilder comparison (Native vs String) : http://jsperf.com/test-dom-builder

DomBuilder.js

;(function(root, doc) {
  function AbstractDomBuilder(tagName, attrs, innerHTML) {
    this.tagName = tagName || 'div'
    this.attrs = attrs || {}
    this.innerHTML = innerHTML || ''
  }
  AbstractDomBuilder.prototype.build = function() {}

  function NativeDomBuilder() {
    AbstractDomBuilder.apply(this, arguments)
  }
  NativeDomBuilder.prototype.build = function() {
    var attrs = this.attrs
      , node = document.createElement(this.tagName)
    // Build properties
    for (var attr in attrs) {
      node.setAttribute(attr, attrs[attr])
    }
    // Inject innerHTML
    node.innerHTML = this.innerHTML
    return node
  }
  root.NativeDomBuilder = NativeDomBuilder

  function StringDomBuilder() {
    AbstractDomBuilder.apply(this, arguments)
    // Use custom array to create properties
    var properties = []
    properties.toString = function() {
      return this.join('')
    }
    this.properties = properties
    // HTML parser
    this.parser = document.createElement('div')
  }
  StringDomBuilder.prototype.build = function build() {
    var attrs = this.attrs
      , parser = this.parser
      , properties = this.properties
      , html = ['<', this.tagName, properties, '>', this.innerHTML, '</', this.tagName, '>']

    // Clear parser
    while (parser.firstChild) {
      parser.removeChild(parse.firstChild)
    }
    // Clean properties
    this.properties.length = 0
    // Build properties
    for (var attr in attrs) {
      properties.push(' ', attr, '=', '"', attrs[attr], '"')
    }
    // Parse HTML String
    parser.innerHTML = html.join('')
    // Return parsed HTML
    return parser.firstChild
  }
  root.StringDomBuilder = StringDomBuilder
}(this, this.document))