George Gkouvousis

Simple, yet effective plugin that once activated, it will eliminate every CSS version tag of WordPress plugins, core & themes.
Bonus: your website will receive a small boost of SEO, you will experience no CSS caching issues anymore and hackers wont be able to recognize your version numbers.
Try its demo <a href="http://apps.8web.gr/demos/wordpress-remove-versions-from-code-plugin/" rel="nofollow ugc">here</a>

No Version Tags

Description: Upon activation, this plugin will automatically eliminate the annoying '?ver=x.x' signs from your perfect code :)

sebastiaandegeus

This WordPress plugin automatically versions your enqueued javascript and css files with a md5 hash to the querystring based on the file content. When the file changes the md5 hash changes and the file will be downloaded and chached again by the browser.

No Version Tags vs Version This