Some time ago, I published a WordPress plugin called WP Category Tag Cloud.
With this plugin, you can display a configurable 2D or 3D cloud of taxonomy terms (like tags, categories or any custom taxonomy) and filter them by tags or categories.
My first use case was to display a list of tags and only show tags used in posts belonging to a give category. For example, if you have two areas in your web site (like a business web page and a blog), and you separate these two by using different categories but the tags can partly overlap, you can use this plugin to define a widget which will only show tags used in posts of the blog category.
And over time, there were a few other use cases which came from web sites I am hosting or from user requests. So this plugin provides many options to define how the cloud should be rendered and what should be contained in the cloud.
The cloud elements can be displayed in many different ways:
as a flat list separated by spaces: [showtagcloud taxonomy=category format=flat number=10 order_by=count order=DESC]
as a bulletted list: [showtagcloud taxonomy=category format=list number=10 order_by=count order=DESC]
as price tags: [showtagcloud taxonomy=category format=price number=10 order_by=count order=DESC]
as rectangular tags with rounded corners: [showtagcloud taxonomy=category format=rounded number=10 order_by=count order=DESC]
as horizontal bars: [showtagcloud taxonomy=category format=bars number=10 order_by=count order=DESC]
as a 3D HTML5 based tag cloud: [showtagcloud taxonomy=category format=array number=10 order_by=count order=DESC]
You can also see this one in action in the side bar of this blog.
Additionally, you can set many options to tweak the way the cloud is displayed:
randomly colorize terms: [showtagcloud taxonomy=category format=flat number=10 order_by=count order=DESC colorize=1]
make less used terms less opaque: [showtagcloud taxonomy=category format=flat number=10 order_by=count order=DESC opacity=1]
randomly tilt terms: [showtagcloud taxonomy=category format=flat number=10 order_by=count order=DESC tilt=1]
all of the above: [showtagcloud taxonomy=category format=flat number=10 order_by=count order=DESC tilt=1 opacity=1 colorize=1]
There are even more options available to make this widget look like the way you want it to. And new options are added in every new version.
In order to make sure the performance is good, you can have the widgets cached and define how long they should be cached. Of course, if you change any setting of a widget , it will be regenerated even if it was already in cache.
The widget can be displayed in the sidebar using a widget, in any post or page using a shortcode or anywhere else using the provided PHP function. For more details, please check the FAQ of the plugin.
There are still a few other features that I have on my list but I feel this plugin has already evolved over the past few weeks into one of the more flexible and powerful term cloud plugins for WordPress.
To give it a try, go to the plugin page on WordPress.org and download the plugin. The installation is as easy as searching for it in the plugin installation age in your WordPress installation (or uploading the folder wp-category-tag-could to the /wp-content/plugins/), activating the plugin through the ‘Plugins’ menu in WordPress and selecting the widget and configure it or using the PHP function or the short code.