firefox

This splits the content area of the browser window as you like

* Choose the "Split Browser to" menu in the context menu. * Choose the "Load in Split Browser" menu in the context menu on link. * Click popup-button on top/bottom/left/right edges of the content area. * Drop links, bookmarks, tabs, etc. to popup-button

You can tile all of tabs as split browsers

keeping track of an unlimited number of usernames, passwords and personal information such as name, address, phone numbers, etc

securely stores this personal data on your computer.

Log into websites with a single click. Fill forms in seconds.

YouPlayer is a video player with playlist

supported sites: Google Video, MetaCafe, MySpace and YouTube

You may add/drag a video link into the playlist and watch it or download it.

Permite personalizar la apariencia de las páginas y la interfaz de usuario

Stylish es a CSS lo que Greasemonkey es a Javascript

Guía del usuario: http://userstyles.org/stylish/help

sites supported by Fireuploader... - Rapidshare.com (NEW) - Photobucket (NEW) - Mosso - Box.net - Flickr - Picasa - Youtube - Facebook - Webshots - Omnidrive - Smugmug - SmeStorage - Google Docs - Snaphappi, a digital photo processing website - Adobe Share (new) - Slideshare (Share your presentations online)

You can upload any number of files at a time. *You can upload files to multiple websites using a single interface (using only one extension). *Ability to add multiple accounts and upload files to each account independently.

Gmail notifier for multiple accounts

Allows you to receive new mail notifications along with viewing account details including unread messages, saved drafts, spam messages, labels with new mail, space used, and new mail snippets

You can use multiple accounts

notifies the number of unread emails

supports - mail.google.com(Gmail & Google Apps) - mail.yahoo.com (yahoo.com, ymail.com, rocketmail.com) - mail.live.com(hotmail.com, msn.com, live.com) - www.daum.net(hanmail) - www.naver.com - www.empas.com - www.nate.com