"Hey, you know what? Firefox is awesome!" someone exclaimed at the other end of the coworking space a few weeks ago. This piqued my curiosity, and I moved closer to see what she was so excited about.

When I saw the feature she was delighted of finding, it reminded me a similar situation several years ago. In high school, I was trying to convince a friend to switch from IE to Mozilla. The arguments about respecting web standards didn't convince him. He tried Mozilla anyway to please me, and found one feature that excited him.
He had been trying to save some images from webpages, and for some reason it was difficult to do (possibly because of context menu hijacking, which was common at the time, or maybe because the images were displayed as a background, …). He had even written some Visual Basic code to parse the saved HTML source code and find the image urls, and then downloaded them, but the results weren't entirely satisfying.
Now with Mozilla, he could just right click, select "View Page Info", click on the "Media" tab, and find a list of all the images of the page. I remember how excited he looked for one second, until he clicked a background image in the list and the preview stayed blank; he then clicked the "Save as" button anyway and… nothing happened. Turns out that "Save as" button was just producing an error in the Error Console. He then looked at me, very disappointed, and said that my Mozilla isn't ready yet.
After that disappointment, I didn't insist much on him using Mozilla instead of IE (I think he did switch anyway a few weeks or months later).

A few months later, as I had time during summer vacations, I tried to create an add-on for the last thing I could do with IE but not Firefox: list the hostnames that the browser connects to when loading a page (the add-on, View Dependencies, is on AMO). I used this to maintain a hosts file that was blocking ads on the network's gateway.
Working on this add-on project caused me to look at the existing Page Info code to find ideas about how to look through the resources loaded by the page. While doing this, I stumbled on the problem that was causing background image previews to not be displayed. Exactly 10 years ago, I created a patch, created a bugzilla account (I had been lurking on bugzilla for a while already, but without creating an account as I didn't feel I should have one until I had something to contribute), and attached the patch to the existing bug about this background preview issue.
Two days later, the patch was reviewed (thanks db48x!), I addressed the review comment, attached a new patch, and it was checked-in.
I remember how excited I was to verify the next day that the bug was gone in the next nightly, and how I checked that the code in the new nightly was actually using my patch.

A couple months later, I fixed the "Save as" button too in time for Firefox 1.0.

Back to 2014. The reason why someone in my coworking space was finding Firefox so awesome is that "You can click "View Page Info", and then view all the images of the page and save them." Wow. I hadn't heard anybody talking to me about Page Info in years. I did use it a lot several years ago, but don't use it that much these days. I do agree with her that Firefox is awesome, not really because it can save images (although that's a great feature other browsers don't have), but because anybody can make it better for his/her own use, and by doing so making it awesome for millions of other people now but also in the future. Like I did, ten years ago.