Copy As HTML Link

It creates a link to the current page when you are copying the text.

AutoCopy

It automatically copies text to the clipboard when the text is selected as the way Trillian or mIrc works and paste into textboxes, the url bar, and the search bar by middle clicking.

CoLT

Colt can be regarded as enhanced edition of Copy Link Text and Copy as HTML Link. CoLT can not only copy the link’s text but also both the link and the link’s text. The copied text can be in BB Code or Wiki format or you can specify the format through the User-defined Format of CoLT

Paste and Go 3

Its feature is that if there is a URL in the clipboard, it allows us to switch to that website directly by only one action instead of pasting on the address bar and then click Go. It works for search too. However, it has a fault that it doesn’t work when you copy via CTRL+C shortcut.

Paste IP

It pastes your IP address or User-Agent in textbox which is convenient for you to post on places like forums.

Copy Plain Text

This is the one I can’t do without. When I copy the text, I want to copy the plain text without the text formatting and text link and this add-on lets me realize this.

CopyAllURLs

It copies and pastes all URLs of open Tab to and from clipboard, but it is not updated to work with the latest version of Firefox.

Table2Clipboard

It makes you easily copy data from a table. By holding down Ctrl key to select the table cells you want and then pressing Ctrl+Shift+c, the selected content is saved to clipboard.

Extended Copy Menu’

It offers options to copy the selected field as plain text or HTML by adding “Copy As Plain Text” and “Copy as HTML” to the context menu. But it needs updating too.

Session Manager

It is good at restoring the state of all windows so that you can reopen these webpage including the (accidentally) closed windows and tabs, which let you save from copying to restore.