While most users want to make sure that copied text from their web browser does not contain any formatting or code some users might just need that. Web developers for instance might be inclined to copy the html instead of the plain text to be able to process it further or use the information to paste it into an editor that is compatible to html code.
One example could be to copy a nicely formatted html table into a rich text editor. It is possible to copy the html manually by looking at the source code, finding the code and text that should be copied and pasting that code into another application.
Copy Code on the other hand automates the process. After installing the Firefox add-on it is simply a matter of selecting the text on the website that should be copied, right-clicking when that is done and choosing the Copy HTML entry from the menu.

The Copy Code add-on for Firefox is a experimental add-on which means that users who want to install it need to log into the Mozilla website first.
Related posts:
Firefox Extended CopyCopy URL To Clipboard When Copying Text In Firefox
Firefox: Edit Forms On Websites In External Editors
Auto Copy Firefox Extension
Copy Tables in Firefox to the Clipboard
Copy And Paste Between Two Computers
Auto Copy Firefox Extension
Paste And Go Firefox Add-on To Speed Up Copy Paste Load Operations


there is another extension which solve this another problem opposite to this problem – when you may want to copy text rather than link called copy link text
Copy Link Text
https://addons.mozilla.org/en-US/firefox/addon/4750
see C.O.L.T.,plain text,html,bb code and more
this add-on will be very useful for bloggers specially in case of copying html code