To check if a particular JavaScript file (including jQuery) is maintained by Microsoft, you can use the following C# code with the help of the NuGet package HtmlAgilityPack to parse the HTML content of the official jQuery website and check for the presence of the Microsoft logo, which often indicates official maintenance:

First, you need to install the HtmlAgilityPack package. You can do this through NuGet Package Manager in Visual Studio or via the Package Manager Console using the following command:

Install-Package HtmlAgilityPack

Next, you can use the code below to check if the jQuery file is maintained by Microsoft:

using System;
using System.Net.Http;
using HtmlAgilityPack;

class Program
    static void Main()
        string jQueryUrl = "";

        bool isMicrosoftMaintained = IsMicrosoftMaintained(jQueryUrl);

        Console.WriteLine($"Is jQuery maintained by Microsoft? {isMicrosoftMaintained}");

    private static bool IsMicrosoftMaintained(string url)
        using (HttpClient httpClient = new HttpClient())
                // Fetch the content of the URL.
                string content = httpClient.GetStringAsync(url).Result;

                // Parse the HTML content.
                HtmlDocument doc = new HtmlDocument();

                // Look for the Microsoft logo in the page source.
                bool isMicrosoftLogoPresent = content.Contains("microsoft-logo");

                return isMicrosoftLogoPresent;
            catch (Exception ex)
                // Handle any exceptions that may occur during the HTTP request or parsing.
                Console.WriteLine($"Error: {ex.Message}");
                return false;

Please note that this approach is based on the assumption that the official jQuery website ( still uses the “microsoft-logo” class or identifier to represent official Microsoft maintenance. If the website changes or the logo’s class name is different, this code may not work correctly. Always ensure to verify and update the code based on the latest website structure if necessary.