By default WordPress supports WLW and adds the following line of code to every page of your website:
<link rel="wlwmanifest" type="application/wlwmanifest+xml" href="https://domain.com/wp-includes/wlwmanifest.xml" />
Windows Live Writer (wlw) is a discontinued desktop blog-publishing application that was developed by Microsoft and distributed as part of the Windows Live suite of apps. The last major release of Windows Live Writer came out in 2012, and the software was completely discontinued in January 2017.