I have been developing this plugin architecture, mostly for fun and education, its a simple Winform with some plugin logic and two plugins, i want to know if there is a better way of doing it.

Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Plugin_architecture
{
    public partial class Form1 : Form
    {
    // -----------------------Plugin logic ----------------------------------

    private static IEnumerable<Type> getDerivedTypesFor(Type baseType)
    {
        var assembly = Assembly.GetExecutingAssembly();
        return assembly.GetTypes().Where(baseType.IsAssignableFrom).Where(t => baseType != t);
    }

    public void invokePlugin(object sender, EventArgs e, string pluginIdentifier) {
        Type type = Type.GetType(pluginIdentifier);
        object instance = Activator.CreateInstance(type);
        MethodInfo method = type.GetMethod("start");
        method.Invoke(instance, null);
    }

    public void registerPlugins() {
        // Register plugins at application startup
        IEnumerable<Type> plugins = getDerivedTypesFor(typeof(Plugin));

        foreach(Type plugin in plugins) {

            LinkLabel pluginLabel = new LinkLabel();
            pluginLabel.Text = plugin.ToString();
            pluginLabel.Click += delegate(object sender, EventArgs e) { invokePlugin(sender, e, plugin.ToString()); };
            pluginContainer.Controls.Add(pluginLabel);

        }
    }
    // --------------------------------------------------------------------------

    public Form1()
    {
        InitializeComponent();
        registerPlugins();
        }
    }
}

Plugin.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

abstract class Plugin
{
/*
 * Base class for plugins
 * Implement the start method and add any functionality you want. The start method will be
 * called each time the plugin is started. Use the stop method to do any nessesary cleanup.
 */

//public void init() { 
//    // Initialize plugin
//}

//public void register() { 
//    // Register plugin in application
//}

abstract public void start();
abstract public void stop();
}

ServicePlugin.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

class ServicePlugin : Plugin
{
override public void start() { 

    const string message = "Yeahh! Plugins!!";
    const string caption = "Plugins!";
    var result = MessageBox.Show(message, caption,
                                 MessageBoxButtons.OK,
                                 MessageBoxIcon.Information);
}
override public void stop() { 
    
}
}

ClientPlugin.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Plugin_architecture.Plugins.ClientPlugin;

class ClientPlugin : Plugin
{
override public void start() {

    Client frm = new Client();
    frm.Show();
}
override public void stop() { 
    
    }
}

Client.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Plugin_architecture.Plugins.ClientPlugin
{
    public partial class Client : Form
    {
        public Client()
        {
            InitializeComponent();
        }
    }
}

The code works great, and should compile without problems.