About me

Developer Information
Name Sebo
User since March 5, 2007
Number of add-ons developed 1 add-on
Average rating of developer's add-ons Rated 4 out of 5 stars

In a little more detail...

Some people may wonder why I am making projects like RExT in my free time. The answer to that is easy: Because i like to program and also to help others.
That's why I am not just active in my own projects, but also help other people with their projects.
At the moment I am participating in the following projects (among others):

  • Firebug (
  • ChromeList (
  • BabelZilla (
  • (

Add-ons I've created

Regular Expressions Tester Requires Restart

Testing tool for regular expressions with color highlighting (including submatches) and helpers for creating expressions

Rated 4 out of 5 stars (27)
1,764 users

My Reviews

MDN: Save With Comment Hotkey

Simple and effective Rated 4 out of 5 stars

It does what it says, simple and effective.
It would even be better if the shortcut could be adjusted.

FireStorage Plus!

Simple tool for inspecting and manipulating storage entries Rated 5 out of 5 stars

This extension is an easy to use storage management tool, which seemlessly integrates into Firebug. It allows you to inspect and edit 'localStorage' and 'sessionStorage' entries, create new ones or delete existing ones.
Can't wait to see it being able to manage the IndexedDB storage.

This review is for a previous version of the add-on (  This user has a previous review of this add-on.

FireStorage Plus!

Simple but nice Rated 4 out of 5 stars

The extension does what it says and integrates well with Firebug.
Now it just needs a way to manage the entries and it will be perfect.


This review is for a previous version of the add-on (1.0.1-signed.1-signed). 


Formerly did what it says Rated 5 out of 5 stars

Also doesn't work for me using FF 6.0.2 + FB 1.8.3.Now, that there are new APIs available (, it should be much easier to get that info.Though note, that there's already an issue integrate this feature into Firebug:, which will probably make this extension obsolete as soon as it is implemented.Since this little extension previously did exactly what the short description says, I keep the rating up. Though it should be updated soon.

This review is for a previous version of the add-on ( 


Well integrated Rated 5 out of 5 stars

Not bad for a first version!
It does what it's name promises. It gives you information about the fonts used inside a page or the current selection.
Unfortunately I don't see any additional info to the WOFF files on the pages I tested this extension with.

This review is for a previous version of the add-on (0.1.1-signed.1-signed). 

UI Fixer

The name already tells everything Rated 5 out of 5 stars

Actually I was just searching for an extension, that allowed me to move the add-on bar icons, which already works pretty fine with this little helper.
But besides that it offers some other interesting features. So I also got back my sorely missed "New Tab" option in the tab context menu.
Personally I don't need the other options, but for everyone, that e. g. wants to move the Firefox button or to move the menu, this is the right tool. Just one little thing I noticed: It seems not to be possible to completely remove the Firefox button from the UI.

This review is for a previous version of the add-on ( Translation

Much improved version Rated 4 out of 5 stars

From the first view I have to say wow! Version 2.4 has pretty much everything you missed in the first simple version.
All the new features work quite well. The points I criticised before (FF 4 compatibility and multi-language) are fixed. Also the inline translation is a great enhancement.
Though as with all big changes there are still some little flaws like not being able to select the languages in the options after hitting "Refresh", an incorrectly aligned inline translation and some others. That's why I just give four of five stars, but all in all a great improvement!

This review is for a previous version of the add-on (2.4.1-signed).  This user has a previous review of this add-on.

Text Complete

Where's the FF4 compatibility? Rated 3 out of 5 stars

Firefox 4.0 is at the ready, so this add-on is urgently calling for an update.
Unfortunately now even the support website redirects to another page...
Non-the-less it's a neat little tool and I like to use it.


Handy tool for managing cookies with seamless Firebug integration Rated 5 out of 5 stars

Great extension, Honza! I'm using it whenever I have to work with cookies.

@Salabim: What do you expect it to do? Editing the expiration date works fine for me. If it doesn't for you, feel free to file a bug at

This review is for a previous version of the add-on ( Translation

Simple to use, but missing options Rated 3 out of 5 stars

Since is the first place for me for searching a translation, this add-on was the right choice for me.
Though there are two problems I want to point out:
1. The extension is not compatible to current versions of Firefox (3.6 and 3.7 pre-alpha; though it was working fine for me when deactivating the version check)
2. is already offering translations into different languages than just EN DE for some time. So it would be nice to have the possibility to select the translation languages (from and to).

This review is for a previous version of the add-on (1.0). 

Modify Headers

Rated 5 out of 5 stars

Very cool thing! This makes modifying HTTP requests very easy!

This review is for a previous version of the add-on (0.6.6). 

Autofill Forms

Easy for simple form filling, but difficult to use for more complex logic Rated 3 out of 5 stars

Autofill Forms is very handy to use for simple form filling. Though there is some space for improvements for more advanced form filling:

1. Assistance for defining dynamic tags
As a web developer sometimes I have to fill out a form with different values for each time I'm filling out the form for checking the form validation or e. g. for simply not getting conflicts of entering the same email address two times. To do so I have to define several little JavaScripts as dynamic tags in Autofill Forms creating random values. Besides random values I often want to insert resp. select a value of a specific list of options like for cities or countries.
Therefore I'd suggest a wizard for dynamic tag editing, especially for creating random values or lists of available field values.

2. Advanced documentation
Filling forms with pre-defined values as trivial as it sounds is not not that easy sometimes (see above). That's why the documentation on the mozdev website could be extended and have some more examples. Especially the most important parts like the field rules, the alternatives and the advanced editor itself are having a lack of documentation and examples.

3. Internal form filling tester
To test the defined form field rules it would be great to have an integrated preview, that generates a form with the specific form fields to show the user how the defined rules apply.

4. UI enhancements
- In the advanced editor there should be a button, that opens a dialog for selecting the defined dynamic tags.
- In the dynamic tag editor the text fields to define a JavaScript rule should expand to a text area when focused
- Allowing drag & drop for profiles and form field rules list

This review is for a previous version of the add-on ( 

Extension Tracker

Useful little tool with flaws Rated 3 out of 5 stars

For all people, that don't know what this tools does: It's a tool for developers showing information about the extensions you created for Firefox by fetching the data from
But I am not the developer of this plugin, so I have some suggestions, too. ;-)
1. There should be options to control, which extensions are shown resp. which information.
2. I am missing an option to open directly the site of an extension instead of just the author's page.
3. It would be cool to have an internal search for extensions/authors inside the options instead of telling the people how to copy the ID.
4. The options dialog should be sized correctly and not be resizable.
5. Please document it!

Chrome List

Indispensable for every add-on developer Rated 4 out of 5 stars

Chrome List already helped me out very often when I was browsing for a function already existing in Firefox or for finding special XULs.
It saves so much time when you don't have to unpack the JAR files of Mozilla to have a look for the things you need.
Though I wished there was an option to search for files or even content in that files as for example the programming framework Eclipse offers it.

This review is for a previous version of the add-on (0.3).