Perfect:
(adj) Completely suited for a particular purpose; complete of its nature or kind.
A perfect open source framework, library, or package is one that never holds me back. My own brainpower, determination, and willingness to search for solutions out in the community are the only limiting factors.

I sometimes get irrationally excited about the possibilities of building things using these tools. I feel like I have secret weapons.
In no particular order, they are:
Redis: A "data structure server" providing seemingly unlimited ways to build cutting edge
data storage + access applications easily. It's just one shining star of the
NoSQL movement, but it's
ease of use, combined with a
multitude of elegant use cases, make Redis perfect for me.
Nginx: A webserver that combines
blazing speed with
minuscule memory usage with
simple configuration. Such a gem.
Django: A web application framework that
does it all - and all
completely documented in shockingly good form on the projects own website. Plus its ever-growing community has a large array of plugin apps to chose from.
jQuery: A JavaScript framework that has an
incredibly beautiful API, and a
dizzying array of plugins that will solve absolutely any problem you face. I don't fear JavaScript anymore, instead I love it.
It's not that I'm an expert on any one of the above - not nearly - but I'm experienced enough to know that, for me, they are best-of-breed.
The reality is there are many more pieces involved in creating a full featured application, so having a selection of perfect pieces will only get you so far when building out a real world app. In fact, there are many other projects
that I really enjoy using, but they all hover just below the "perfect" mark.
Finally, and somewhat obviously, is that what is perfect today will be by no means perfect tomorrow. Without constant evolution and improvement,
any one can be eclipsed by another - in some cases in short time spans. What I present above are just my opinion of what is "perfect" today.
What perfect open source secret weapons do you have?
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