Tim West

That's correct; this application is currently built with the .NET Framework which is Windows-only. A browser-based version exists that might meet your needs. I've never used this app, so I...

You could probably modify [`VisitPropertyDeclaration`](https://github.com/praeclarum/Netjs/blob/126cb625cade51cf44e459a0fac002125b2d950f/Netjs/TsOutputVisitor.cs#L2375) to transform the name: ```C# propertyDeclaration.Name = char.ToLower(propertyDeclaration.Name[0]) + propertyDeclaration.Name.Substring(1); ```

I don't think `Optional` is a type defined by .NET, which is why the expression remains as-is. The optional type is [`Nullable`](https://docs.microsoft.com/en-us/dotnet/api/system.nullable-1?view=netframework-4.7.2). From my experience, the transpiler can correctly handle...