Windows版だがこんなもんでどうだｗ（終了はAlt+F4)

using System;using System.ComponentModel;using System.Windows.Forms;using System.Drawing;
static class P{static bool fl=true;static F[] f=new F[4];static void Main(){f[0]=new F(1);f[0].Top=-f[0].Height+100;
f[1]=new F(1);f[1].Top=400;f[2]=new F(2);f[2].Left=-f[2].Width+100;f[3]=new F(2);f[3].Left=600;
Application.Run(f[0]);}class F:Form{int m;public F(int n){Visible=true;FormBorderStyle=FormBorderStyle.None;
BackColor=Color.Black;m=n;Width=Height=9999;TopMost=true;MouseDown+=Md;MouseMove+=Mm;}
protected override void OnClosing(CancelEventArgs e){if(this!=f[0]&&fl){fl=false;f[0].Close();}}
protected override void OnMove(EventArgs e){if(m==1){Left=0;Width=Screen.PrimaryScreen.Bounds.Width;}else
{Top=0;Height=Screen.PrimaryScreen.Bounds.Height;}}private Point p;private void Md(object s,MouseEventArgs e)
{if((e.Button&MouseButtons.Left)>0){p=new Point(e.X,e.Y);}}private void Mm(object s,MouseEventArgs e)
{if((e.Button&MouseButtons.Left)==MouseButtons.Left){Left+=e.X-p.X;Top+=e.Y-p.Y;}}}}