Firefox 57 is out, and you need new add-ons

Yesterday, the Mozilla people released Firefox version 57. And with it, they have removed the old "XUL" based add-on system. So all add-ons must now use the new WebExtension API. Unfortunately, many add-ons (including a lot that I use) have not been updated yet, despite Firefox issuing warnings for the last several revisions. In many cases, the authors have abandoned the code, and in others, I don't think they care enough to want to re-implement it for the new API.

The result is that I've had to remove and replace many of my favorite add-ons. Here's a list of what I had to change and what I think of the results.

Adblock Plus

Fortunately, Adblock Plus has been upgraded to use Web Extensions. So just perform an upgrade and get the latest version. They changed the user interface a bit and I prefer the way the older (XUL-based) version looked, but all the same functionality appears to be present.

DOM Inspector

The DOM Inspector add-on allows you to examine the structure of web pages at a detailed level without having to read pages and pages of nested/embedded HTML/CSS source code. Despite having been originally developed by Mozilla people, it appears to have been abandoned. It has not been upgraded to Web Extensions and therefore has no replacement.

Fortunately, it isn't necessary anymore. For many years now, Firefox has had a built-in DOM inspector that in many ways is better than the add-on. Just right-click on some part of any web page and select "Inspect Element" from the pop-up menu. The inspector will appear at the bottom of the window and provide all the access you need.

Flashblock

Flashblock is a really important tool that should be used by everybody who has installed Adobe Flash (which is almost everybody). It looks for Flash content on a web page and replaces it with a placeholder icon. The Flash object will not load unless you click on the icon. There is a white-list you can use to pre-authorize some web sites, to avoid the need to click on every icon (especially important for sites that use a lot of Flash.

Although Firefox's built-in "ask to activate" mechanism partially eliminates the need for Flashblock, I have found that it is not sufficient. Ask-to-activate forces you to enable/disable Flash for an entire page (or an entire site). It doesn't let you individually pick which Flash objects to load and which to block. This is important because in many cases, a single page will have both Flash content you want to load (like the video or app you want to access), but also Flash content you want to block (like advertisements).

Flashblock appears to be abandoned (last update was over two years ago and it's home page hasn't been updated for much longer. Fortunately, there exists Flash Block (Plus) which is compatible with Web Extensions.

I don't like the user interface as much (it consumes a lot of screen real-estate and the placeholder icons are massively oversized), and I don't yet know if the whitelist semantics are the same as the original Flashblock, but it gets the job done.

GMail Watcher

GMail Watcher is a simple add-on (not available from Mozilla) that displays an icon in a toolbar. The icon changes color and makes a sound when you have unread mail in your GMail box. Clicking on it opens a browser window with the GMail page so you can read it. Nice and simple and useful.

The author, Sonthakit has not yet upgraded GMail watcher to use Web Extensions. I don't know if he will or not.

Until then, I found that Gmail Checker Simple is almost as good. There are many mail-checker add-ons, but most are heavyweight apps that monitor multiple mailboxes and let you read/compose mail from within the add-on. I don't want anything that complicated. This one just does what GMail Watcher did - periodically check for mail and display a badge on the icon when there is unread mail in the box.

It's not as nice as Sonthakit's add-on. It doesn't make sound when mail arrives and it always opens GMail in a new tab (GMail Watcher could be configured so a left-click opens GMail in the current tab and center-click opens it in a new tab). But it does what I need it to do.

GMarks

This is the one I miss the most. Gmarks loads your Google Bookmarks and presents them as a menu in the menu-bar or in the Bookmarks toolbar. Unfortunately, it was abandoned a long long time ago. It's last significant update was in 2009. Since then, there have only been trivial changes. It was digitally signed, to allow Firefox to load it, but nothing more.

I personally think GMarks is by far the absolute best add-on for Google Bookmarks. And it appears that I'm not the only one who thinks so.

Over the years, it broke several times (because Google changed their interface) and various intrepid developers on its support forum released their own private updates in order to keep it working. But when XUL-based add-ons went away, GMarks stopped working for good. It isn't going to come back unless someone rewrites it to use the Web Extension API. I don't know how hard this is, nor do I know if anybody has the time or desire to do so, but I am hoping that someone eventually will and I periodically check the support forum just in case.

But I rely on having a menu with all my Google Bookmarks so I did a lot of searching for something I can use. Unfortunately, there aren't many choices and even fewer good ones. I ultimately selected hccbe Google Bookmarks Extension. It is about the most minimalist (but not minimal enough for me) extension I could find. I will be using it until something better comes along. If I'm lucky, then maybe someone will port GMarks to the Web Extension API - that would be perfect, but I'm not counting on it.

Navigate Up

Navigate Up is a trivially simple add-on. It presents an up-arrow that you can place in a tool-bar or the location bar. When you click on it, your browser goes "up" a level - the last term of the URL is stripped and you visit the resulting page.

Rather than replace the add-on with a Web Extension version, the author released a new add-on. Navigate Up WE is pretty much the same extension, but using the Web Extension API. The current version doesn't let you put the arrow in the location bar, but aside from that, it works great.

User Agent Switcher

User Agent Switcher is a convenient little tool. It presents a menu where you can tell Firefox to identify itself as some other kind of browser by changing the user-agent string it sends to web servers. This is useful for testing some kinds of dynamic content and it can help work around brain-dead web sites that may unnecessarily block some browsers, browser versions or operating systems.

This add-on has been abandoned (the last update was over 7 years ago), but I was able to find User-Agent Switcher (revived) which appears to be a re-implemented version of the old package, with a new UI and using the Web Extensions API

In conclusion

So there's the wrap-up of what I changed as a part of migrating from Firefox 56 to 57. I have put all the above add-ons in my favorites list so you can just load them directly if you are so inclined. If you have any suggestions for better replacements or would like to share your favorite Firefox add-ons, feel free to leave comments here.