- Acebug
- Add-on SDK Examples
- AdMatrix Analytics
- Adobe BrowserLab for Firebug
- Advanced Frame Designer
- Affilorama SEO Toolbar
- AMF Explorer
- anchors-reveal
- Animat
- ASP.NET Viewstate Viewer
- Auto-Open Browser Console
- Auto Reload
- awesome-timestamp
- awetest recorder
- Blank Scratchpad
- Browser Calories
- Browser Console Button
- CacheToggle
- Chrome List
- CodeBurner for Firebug
- CodeBurner for Firefox
- Colorblind Design
- Colorizer
- colorPicker
- ColorZilla
- Console2
- Context Font
- CookieWatcher
- Copy as Markdown
- Copy HTML
- Copy Link as HTML or Markdown Code
- CSS Reload
- CSS Reloader
- CSSsir
- CSS Usage
- CSSViewer
- Deepest Sender
- Default Responsive Design View
- defyFormValidation
- Dev Buttons
- Developer Tools - toolbar button
- DevPrefs
- DevTools toolbar items
- Display #Anchors
- docked JS-Console
- DOM Inspector Toolbar Button
- Dummy Images
- Dust-Me Selectors
- EditCSS
- Element Digger
- Event Spy Too
- Execute JS
- Extension Developer
- Extension source viewer
- Extinctor
- eyedropper Button
- eyedropper_restartless
- favicollect
- fi
- Firebug
- Firebug Autocompleter
- Firebug Paint Events
- FireClosure
- FireDiff
- Firefinder for Firebug
- FireFontFamily
- Firefox Accessibility Extension
- FireHiddenView
- FireMobileSimulator
- Firepicker
- FireQuery
- FireRainbow
- FireRuler
- FireSSH
- FireStorage
- FireStorage Plus!
- fireword beta
- FireXPath
- Flashbug
- FlashFirebug
- Flashlight
- Fontface Ninja
- Font Finder
- Font Finder(737353)
- fontinfo
- font infos
- Font Inspector
- Force CORS
- Foxy Detective
- Foxy SEO Tool
- fragment
- french-press
- Fresh CSS
- Fresh Dom Tree View
- friendly bug
- fulmo
- Generic CSS Loader 2
- Good Website Inspector
- Graphical Timeline of Events
- GridFox
- HackBar
- Holmsie
- HTML 5 Validator
- HTML Color Coder
- HTMLEditor
- HTML Element Detector
- HTML Regex Data Extractor
- Html Validator
- HttpRequester
- HTTP Resource Test
- IE NetRenderer
- ImageExchange
- Image Map Editor
- Image Spider
- IndexedDB Browser
- Inline Code Finder
- Inline Code Finder for Firebug
- Input Colourer
- Inspect Object
- InspectThis
- Javascript Command
- JavaScript Deobfuscator
- JavaScript Terminal
- Javascript View
- JS Deminifier
- JSLinter
- JSON-DataView
- JSONView
- jspanel
- JSView
- L-Square
- Landmark Navigation via Keyboard or Pop-up
- Library Detector
- Live Edit
- Live Editor
- Live editor for CSS and LESS - Magic CSS
- Local Load
- Magnifier
- Measure-it
- MeasureIt
- measurer
- Meta Generator Version Check
- microspect
- MileWideBack
- MiniBrowserX
- MobileView
- More Display Resolutions
- mozcmd
- My Scratchpad
- notice noindex
- Open TortoiseSVN
- OpenWAX
- Originz
- PageDiff
- Page Speed
- Palette Creator
- Performance-Analyser
- Performance Map
- pesticide
- Phoenix
- PHPdebugger
- Pixel Perfect
- PixelZoomer
- PixeRoll
- PopupInspector
- quit gcli
- Rainbow
- Regxer
- Remote XUL Manager
- Remove Temporarily
- retire.js
- rightclickxss
- rogumecopy
- rogumetool
- ruler
- ruler_guides
- Save Back to File from DOM
- Scratchpad
- Scratchpad Button
- Scratchpad Editor
- Screen sizes
- Selenium IDE
- SenSEO
- SEO Doctor
- SEOpen
- SEO Toolbar by SEOmoz
- Server Switcher
- Sharp Color Picker
- Show external css/js files
- showHTML
- Simple Base64
- Simple Markup Validator
- Simple Storage Editor for Addon SDK
- SiteCheckr
- Site to Panel
- source-gcli-jetpack
- SourceEditor
- Speed Page
- SpeedView
- SQL Inject Me
- steplog
- Strike Out Nofollow Links
- Style Editor
- Style Guide Generator
- SummerCSS
- Tag Attribute Finder
- Text To Code Ratio
- TextToTag
- ThumbnailCopy
- toggleconsole
- Toggle Development Profile Prefs
- Toggle Paint Flashing
- toggleresponsive
- TortoiseSVN Menu
- Try IT Yourself HTML5 editor
- TypeGauge
- UxU - UnitTest.XUL
- Validate Me
- Validator
- Validaty
- View Scratchpad As HTML
- View Scratchpad As HTML Jetpack
- View Source
- View Source Chart
- Wappalyzer
- WatchPug
- watir-context-menu
- WCAG Contrast checker
- Web Console
- Web Developer
- Web Developer Toolbar Button
- Web Metrics Framework
- Web page to source code & viceversa
- Wikipedia-References-Creator
- WSDL Preview
- X-Ray
- Xinha Here!
- XmlUtils
- XPath Checker
- xpathprototyping
- xqjs
- XSS Me
- XUL gear
- YSlow
- Zaqwes Guide Lines