I understand the meaning of "long tail", but not sure what it means in this context. Is this an infosec term? I work in webdev and have never heard it used. Are you referring to less-commonly used web app frameworks?

Less commonly used web apps; they tend to have poor security because no-one has cared/known enough to make them not horribly insecure.

> But seriously, I got started by writing exploits for long tail web apps.

I lovingly refer to this as "clubbing baby seals" and it is overwhelmingly common among younger hackers looking to polish their skills. :-x