Slimbox
BarackSlideshow
Slideshow
PathFusion : multibox
SqueezeBox ? Expandable Lightbox
MediaBox
Javascript Image Gallery Using Mootools (part 2)
Sliding Tabs
Mootabs
SimpleTabs ? Unobtrusive Tabs + Ajax
FormCheck
fValidator
ForMoo ? Form Tools for Mootools
MOOdalBox ? an HTML Lightbox
Javascript Fisheye Example
FancyUpload ? Swiff meets Ajax
UI TESTS :: Drop Menu
ddmenu
Fancy Menu
Mootools :: Drop Menu example
UvumiTools drop down menu
Drop Down Menu
MenuMatic ? Drop Down Menu
PathFusion : image menu
Calendar (date picker)
Unobtrusive JavaScript date-picker widgit
Another date picker
wysiwyg ? mootools
Pathfusion ? Sortable table
Mootable
Reflection.js
Autocompleter
Tipsx3
Mootools Split Panes
iCarousel
MooSocialize
Rounded Corners

source