 Let's see how we can add colorizations and syntax highlighting to languages that Visual Studio does not support out of the box. So here I have a file open. It's a stylus file. Stylus is a language that is a variation of the CSS language for web development. You can see it opens up here just as plain text. I don't have any colors. So what do I do? Well, first of all, I'm going to open the extension manager to see whether there are anything, any extensions supporting stylus out on the marketplace. We see there's one extension here, but it doesn't seem to have anything to do with colorization or syntax highlighting. So I'm going to go to the website. Here's the stylus website and see if they have any extensions here. It doesn't look like they do, but they do have a GitHub repository. So let's see what they got there. And we can see here they have something called TM Bundle. TM Bundle, TM stands for TextMate. And so TextMate is what powers a bunch of editors out in the wild, Visual Studio Code, Sublime, etc., with syntax highlighting. And it's a format. We can take a look at what it looks like here. TM language, that is one of the supportive file names for this TextMate syntax. So TextMate syntax can either be in XML or in JSON format. There's also YAML, but I think JSON and XML are the most common ones. And oftentimes the file extension used for the XML ones are either like here, TM language or P-List. But either way, they're the same format in XML. Okay, so this is how a lot of extensions they syntax highlight the stylus language. So how do we get the TextMate grammar file, which is this one, into Visual Studio? Well, first of all, I'm going to install an extension. So let's search for TextMate. And we can see I already have the TextMate grammar template installed. And that allows me to create a new project called a TextMate. Let's search for TextMate, a TextMate grammar extension. Let's call this stylus language. That's the name of my project. So here we see the project, which is an extension project. So I'm actually writing a Visual Studio extension. And we can see that this template gives me sort of everything I need in order to support this language. And it opened the language.plist file, which is this XML document. So now I can simply go back out to the stylus XML document here and just copy it and paste it into Visual Studio like this. We can see it applies to two file extensions, Style and Stylus. I'm going to save this. So had this been a JSON document, I would have to have changed the file I'm here to .json. And all I need to make sure is that for this language file, this grammar file, that the build action is set to content and the include in v6 property is set to true. So now I have my language definition. This is basically how this has all the regular expressions and everything I need to colorize this language. So now I can go into this other file here, the package step file, which lets me create an icon for this new language. So in Solution Explorer, I may want to have an icon that corresponds to the language. And Visual Studio ships with a bunch of icons. And we can actually see them right here. So if we jump in, we see the known moniker is here. So it's almost 4,000 icons. And so I can select one that's really good that has to do with CSS and styling. And I want to use a particular icon. There's a lot to choose from. But I want to find one that I can reuse. So I'm going to just search. I know there's one called Airbrush. So let me just copy this, Airbrush. I'm going to paste that in right here. And we're going to change this to the file extension to style like this. I'm going to copy it because we are supporting two file extensions here, style and stylus. We both give them the same language. And finally, I'm going to open my V6 manifest, which is the metadata about my extension. And we can see here, we're going to make sure that we have a good title for the extension. We should have a good description and some tags and a license file would be good. But let's just leave it at this. And now to test, I'm just going to hit Control-F5, which means start without debugging. I could debug, but there's not really anything to debug here. There's no C-sharp files, for instance, that I can set a breakpoint at. So I'm just going to Control-F5 this. And the experimental instance starts up. So this is the same Visual Studio that I built my extension in. Let's going to start up and have the extension already installed. So let me open a project. So now my project has loaded. And we can see here, I have a stylus file. We see the icon showing up being that airbrush icon. And if I open the file, we see that I get colorization. And I get outlining or code folding. And I get basic auto completion as well, based on symbols found in the same document. So let's open the extension manager to see that the extension that we had is in fact an extension installed like any other extension here. And we may want to take this extension and publish it to the Visual Studio Marketplace or send to our friends or whatnot. And so if we go back to our projects here, if we open the output directory, so the bin folder and debug in this case, we can see we have the stylus language.v6 file right here. And that is our extension. So the whole support for the stylus language that we just saw working is captured within this extension that can install into any Visual Studio out there. Thank you.