As mentioned above, Skeleton is a lightweight CSS framework (or boilerplate, if you prefer this definition) created by Dave Gamache. More specifically, it's two CSS files: the popular normalize.css file and the skeleton.css file.
Skeleton Css vs. UIkit , which is better?
Difference and similar
|Source model||Open Source||Open Source|
|Icon set||No||UIkit comes with its own SVG icon system and library with a growing number of outline icons|
|NPM Pakage||No||yarn add uikit|
Skeleton Css vs UIkit reviews
Although Skeleton is usually called a framework, it is largely a boilerplate. There are no extensive components list, nor are there any custom jQuery integrations. You get a simple, no-frills boilerplate that you can later customize.
The code is pretty clean and follows well-defined conventions.
Every aspect of the framework is designed to be modular, this way designers can easily choose which components to add to their stylesheet without risking to damage the overall style.
There are plenty of ready to use themes available from the official website. You can choose the theme that you want to use from the dropdown menu and then download the CSS, LESS or SASS file for that theme to use for the website.
UiKit is not a very popular framework, especially compared to other options. As such it may be hard to find learning resources other than the official documentation or it may be more likely for development of UiKit to be dropped than for another more popular framework
Development is mostly done in-house and not publicly available.