Plain Javascript and GWT
If you are considering developing a substantial system based on Javascript, we would always recommend that you approach the development using SmartClient or Smart GWT. See the RIA Development page for more details of the benefits of developing Rich Internet Applications using a proper AJAX framework with a designed client-server architecture and extensive server-side support.
However, we also have long experience working directly with hand-crafted Javascript, with helper libraries like jQuery, and with plain GWT apps (as opposed to Smart GWT). We are able to offer support services for legacy applications that use Javascript or GWT, and we can also assist with the development of small or one-off Javascript or GWT projects where there is some reason not to take advantage of of a proper AJAX framework