For development I choose to use tools which make the code transparent. Hence I prefer to use simple text editors over IDEs(although I like IntelliJ for Java code), or browsers that have good builtin support for debugging over closed/magical ones(hence Firefox/Chrome/Safari over IE).

Recently I switched to Chrome as my primary browser since it promised to have all the add-ons to make it comparable to Firefox. On the contrary, in fact it still lacks the power and the flexibility of Firefox for development. Here are a few reasons why Firefox is still better at supporting development:

• greasemonkey for Firefox works with XMLHTTPRequests for different origin – greasemetal (now userscripts) for Google Chrome has still not been able to fix this issue.
  “GM_xmlhttpRequest is same-origin only.” – User Scripts .
• A number of add-ons on Firefox show useful information on the status bar – I use DCurrency, CruiseControl Monitor.
• Selenium IDE is available for Firefox – a big plus when I am trying to record and play while I am trying to debug some apps.
• In the minimal view my frequently used bookmarks always show in Firefox -Google Chrome shows them when I open a new tab only. Maybe a minor annoyance but I cannot reuse the current tab with a single click access to my bookmarks.
• Minor annoyance – when I maximize the window on OSX Google Chrome expands only vertically. Firefox does not have this problem.
• Even with proxy switchers Chrome depends/modifies system proxy settings(diabolical). When using on Windows changing the proxy on IE will affect Chrome and vice-versa.

“Chrome uses system’s proxy settings (IE proxy settings on Wndows) because it
doesn’t have its own proxy settings yet (see http://crbug.com/266).
Therefore, changing Chrome’s proxy settings using Switchy will also affect the
system proxy settings.” – quote from Proxy Switchy! extension.

That means when I use Chrome as a browser with tools like Sahi, it will affect how other things work.

In conclusion, for now Firefox is the best browser for development.