February 11, 2013 By Adam,
Expression Engine (EE) is best known for its capacity to be a very customizable system, a lot of which comes from EE's ability to add or extend functionality by way of Add-Ons.  In layman's terms, much like an operating system, EE comes with a set of “apps” to cover the basic necessities and those apps are called Add-Ons.  For developers, EE  is best known for its active community backing. There are many commercial Add-Ons out there, but there are just as many free and open source Add-Ons  available that are not only great because they are free but also because they add functionality and help the overall performance of your site. While every EE project can be quite unique, there are a few that should be a part of every install.  Below I list the 8 free/open source must have Add-on's for Expression Engine.

IfElse

One strange quirk with EE's native advanced conditionals is that all the content within the conditional tags are parsed, with the conditional only determining what is displayed on the final output of the template. This can affect the performance of pages with many calls to modules like {exp:channel}, that must be processed but may not be displayed. But with the use of the IfElse plugin, this issue is now alleviated.
IfElse on Devot-EE IfElse on Github

Switchee

From the same developer of IfElse and in a similar fashion comes Switchee. This plugin solves the same issue as IfElse, but by use of switch statements.
Switchee on Devot-EE Switchee on Github

SEO Lite

One of the best solutions to add and maintain titles and meta tags is SEO Lite. With some simple setup and easy interface, it's a breeze to add unique SEO data to each of your pages and entries.
SEO Lite on Devot-EE SEO Lite Developer Site

Minimee

While there are many options to go about combining and/or minifying css and javascript files, Minimee is a great solution that integrates this functionality into EE. This extension has a wealth of parameters and configuration settings to customize the processing of each tag.
Minimee on Devot-EE Minimee Developer Site

Deeploy Helper

Deeploy Helper is the quickest and simplest way to change configuration settings. This is most useful when migrating EE across multiple environments.
Deeploy Helper on Devot-EE Deeploy Helper Developer Site

HackSaw

This plugin solves the seemingly simple issue of limiting the output of the number characters from entries. I find this to be one of the most robust options available, with the ability to limit by characters, words, and allowing specific html tags.
HackSaw on Devot-EE

low-Seg2Cat

If you ever use a category within your url, Low Seg2Cat is a very useful plugin. It adds the ability to get a category id from a url segment, assuming the url segment is the same as your category name, which is case sensitive.
Low Seg2Cat on Devot-EE Low Seg2Cat Developer Site

SnippetsSync

While SnippetsSync is not an absolute must, it is very useful if you like having your content saved as files. This module adds the ability to save Snippets and Global Variables as files within your templates folder.
SnippetsSync on Devot-EE SnippetsSync Developer Site
Chris Limon is a Front End Developer at DO. He has a magnificent beard.

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