If you have an existing web site, you can open it in Microsoft WebMatrix. There are some caveats (which I have noted below), but overall it works quite well. Let’s suppose you have a Wordpress site:
1) Start WebMatrix
2) Click Site from Web Gallery. Walk through the wizard and install Wordpress locally. This will make sure that all the application dependencies (such as PHP and MySQL) are installed. More importantly, WebMatrix will now have all the configuration it needs to publish this site.
3) Click Publish in the ribbon
4) Enter publishing settings. I recommend Web Deploy because you can publish databases as well as files using this technology. You can learn more about entering settings here.
5) Next, an all-important step: click the dropdown under the Publish button and click “Download published site…”. This feature only works with the Web Deploy protocol (caveat!) but it lets you download a full copy of your live site.
6) Make any changes you want and click Run in the ribbon.
7) If the site looks good, click Publish.