Unlike Mozilla firefox does not have a tools-web development option by default any more where you clild lunch the dom inspector. You can use this addon from mozilla to use the feature. Get the addon form the following link. https://addons.mozilla.org/en-US/firefox/addon/1806
Chatzilla is a IRC client as a addon to Mozilla Firefox web browser. It is mainly used by hackers and IT professionals. One should not use this addon without experience.
I would start by browsing the UI & Macros forum at the site in the related links. It is on the official wow forums and will give you a huge head-start in your addon development.
Yes, you can, however, not very many people would know about them. Most people tend to stick to the major addon sites that have tools that help addon authors. Sites like Curse and WoWInterface are better equipped to serve your addon to large audiences.
Healbot is an addon, which means it is third-party software. It is most often downloaded from a game or addon site like Curse, WoWInterface or the like. If you are unsure, check if any of your online friends use addons, and where they get them. You can also google "healbot addon" and find the download results.
If you use the Down-it-all-addon for Firefox (and maybe Chrome), there is an option to add a prefix to the file name while downloading them. Its an awesome addon, check it out :D
It is an addon that you buy from steam to use with other games to give them more features.
A must have addon for all raiders in World of Warcraft is Deadly Boss Mods, also known as DBM. This addon will cause warnings to pop up on your screen when important things are going to happen. An example of this would be on the first boss in Heroic SFK. DBM will tell you to interrupt his self heals and will also warn you about when he about to transform towards the end of the fight.
To utilize both, you can install Firefox and then install the 'Coral IE Tab' addon to use IE inside of Firefox's interface. https://addons.mozilla.org/en-US/firefox/addon/10909
No, addons do not cost money. As a matter of fact, Blizzard recently changed their Terms of use and Acceptable Use Policy to require that addon makers NOT charge for their addons, although they can ask for donations on the addon maker's website.
use an addon by the name of "https everywhere".
download the addon. Should be on a zip file. Simply extract the file. place the folder with all the files in your >world of warcraft>interface>addons folder.