You might just dislike JavaScript libraries and the trend around them, or the project you’re currently working on might be too small for a JavaScript library. In both cases, I understand, and after all, who am I to judge you? I don’t use a library myself either (at least not one that you could’ve heard about 😉 ), even though I admire the ingenuity and code quality of some.
However, when you take such a brave decision, it’s up to you to take care of those problems that JavaScript libraries carefully hide from your way. A JavaScript library’s purpose isn’t only to provide shortcuts to tedious tasks and allow you to easily add cool animations and Ajax functionality as many people (even library users) seem to think. Of course these are things that they are bound to offer if they want to succeed, but not the only ones. JavaScript libraries also have to workaround browser differences and bugs and this is the toughest part, since they have to constantly keep up with browser releases and their respective bugs and judge which ones are common enough to deserve workaround and which ones are so rare that would bloat the library without being worth it. Sometimes I think that nowadays, how good of a JavaScript developer you are doesn’t really depend on how well you know the language, but rather on how many browser bugs you’ve heard/read/know/found out. 😛
The purpose of this post is to let you know about the browser bugs and incompatibilities that you are most likely to face when deciding againist the use of a JavaScript library. Knowledge is power, and only if you know about them beforehand you can workaround them without spending countless debugging hours wondering “WHAT THE…”. And even if you do use a JavaScript library, you will learn to appreciate the hard work that has been put in it even more.