'''Motivation'''

[tdom] is much faster than the tcl-only implementation [TclDOM]. The usage syntax for both APIs is very different. The idea is to adjust the syntax of [TclDOM] that it can be used as a dropin replacement for [tdom] if the latter is not available for a certain platform. So code like the following can be written.

  proc createHTML {} {
        set text "Sample page"
        set doc [dom createDocument html]
        set root [$doc documentElement]
        set head [$doc createElement head]
      
        set title [$doc createElement title]
        $title appendChild [$doc createTextNode "$text"] 
        $root appendChild $head
        $head appendChild $title
        $root appendChild [$doc createElement body]
        foreach style {jsComponents.css dg-mpimg.css} {
            set link [$doc createElement link]
            $link setAttribute rel stylesheet
            $link setAttribute text text/css
            $link setAttribute href /css/$style
            $head appendChild $link
        }
        puts [$doc asHTML]
    }
  
    catch {package require tdom}
    if {[info commands dom] eq "dom"} {
        puts "Output via tdom"
    } else {
        puts "tdom not supported on this platform"
        puts "falling back to TclDOM
        snitDom dom
        puts "Output via tcl::dom snitDom"
    }
    createHTML

'''TclDOM changes'''

TclDOM is missing some node/element commands so I was adding them into the source code of dom.tcl.
Here comes the diff:

 $ diff tdom0.8.1.vfs/lib/tcldom3.0/dom.tcl /d/tcl-lib/tcldom3.0/dom.tcl 
 1211,1249d1210
 <         *stChild {
 <             # firstChild or lastChild
 <             set result [dom::tcl::node cget $token -$method]
 <       }
 <         *Sibling {
 <             # previousSibling or nextSibling
 <             set result [dom::tcl::node cget $token -$method]
 <         }
 <         hasAttribute {
 <             if {[dom::element getAttribute $token [lindex $args 0]] eq ""} {
 <                 set result false
 <             } else {
 <                 set result true
 <             }
 <         }
 <         *Attribute {
 <             switch $node(node:nodeType) {
 <                 textNode {}
 <                 default {
 <                     if {[llength $args] == 1} {
 <                         set result [dom::element $method $token [lindex $args 0]]
 <                     } else {
 <                         set result [dom::element $method $token [lindex $args 0] [lindex $args 1]] 
 <                     }
 <                 }
 <             }
 <         }
 <         selectNodes {
 <             switch $node(node:nodeType) {
 <                 textNode {}
 <                 default {
 <                     if {[llength $args] == 1} {
 <                         set result [dom::selectNode $token [lindex $args 0]]
 <                     } else {
 <                         set result [dom::selectNode $token [lindex $args 0] [lindex $args 1] [lindex $args 2]]
 <                     }
 <                 }
 <             }
 <         }
 3005,3006c2966,2967
 <         # dgroth fixes bad browser behaviour with <div foo='bar'/> tags
 <       append result "></$nsPrefix$node(node:localName)>$newline"
 ---
 > 
 >       append result />$newline