Possibly dumping JQuery for smaller solutions

The last couple of days I managed to briefly spend some time to investigate different JavaScript frameworks similar to JQuery. So far nothing practical, just checking what is available and what could be of use. The idea is to reduce downloading time and improve performance especially on older computers and mobile devices which have memory limits.

Knockout.js and Backbone.js look promising according to the following discussion:
http://stackoverflow.com/questions/5112899/knockout-js-vs-backbone-js-vs

Either of them in their minified form have a roughly 4KB file size. as opposed to other like JQuery for example which are in the double or triple digits. For low-end mobile phones this becomes a problem. I have seen some nasty error messages on mobile phones due to out of memory when loading some websites as well as serious slowdown.

What has been showing up lately a lot as well is Node.js which is server-side and cannot just simply run on every website. Node.js also uses V8 JavaScript which might not be supported yet by all browsers on all hardware.

Obviously some of these frameworks are for specific purposes only, but might prove to be useful once I have had some serious experimentation time.