Dihybrid Punnet Generator written in JavaScript, because I was too bored to do it manually in biology class. Not sure if writing this saved me any time, but it works.

dihybrid-punnet-generator.js

/*
To use, run the function where m and f are the genotypes of the parents, and c is an object of the alleles and what they do. For example:
  generatePunnet("RRBb","rrbb",{"R":"running","r":"waltzing","B":"black", "b":"brown"})
will output:
  R: running
  r: waltzing
  B: black
  b: brown

       rb   rb   rb   rb   
  RB   RBrb RBrb RBrb RBrb 
  Rb   Rbrb Rbrb Rbrb Rbrb 
  Rb   Rbrb Rbrb Rbrb Rbrb 
  RB   RBrb RBrb RBrb RBrb 

  Genotypes: 8 RBrb, 8 Rbrb
  Phenotypes:
  running, black: 8
  running, brown: 8
*/
function generatePunnet(m, f, c){
 var al = Object.keys(c);
 var p = [[], [], [], []];
 var ml = [m[0] + m[2], m[0] + m[3], m[1] + m[3], m[1] + m[2]]
 var fl = [f[0] + f[2], f[0] + f[3], f[1] + f[3], f[1] + f[2]]
 var ph = {};
 for(var x = 0; x < 4; x++){
  for(var y = 0; y < 4; y++){
   p[x][y] = ml[x] + fl[y];
   if(ph[p[x][y]]){
    ph[p[x][y]]++;
   }else{
    ph[p[x][y]] = 1
   }
  }
 }
 var r = "";
 var spaces = " ";
 for(var i = 0;i < al[0].length;i++){
  spaces += "  "
 };
 r += al[0] + ": " + c[al[0]] + "\n";
 r += al[1] + ": " + c[al[1]] + "\n";
 r += al[2] + ": " + c[al[2]] + "\n";
 r += al[3] + ": " + c[al[3]] + "\n\n";
 r += spaces + "  " + fl[0] + spaces + fl[1] + spaces + fl[2] + spaces + fl[3] + spaces + "\n";
 for(var x = 0;x < 4; x++){
  r += ml[x] + spaces;
  for(var y = 0;y < 4; y++){
   r += p[x][y] + " "
  }
  r += "\n"
 }
 r += "\nGenotypes: ";
 for(var o = 0;o < Object.keys(ph).length;o++){
  r += ph[Object.keys(ph)[o]] + " " + Object.keys(ph)[o];
  if((o + 1) < Object.keys(ph).length){
   r += ", "
  }
 }
 r += "\nPhenotypes:\n";
 var ph = {};
 for(var x = 0;x < 4;x++){
  for(var y = 0;y < 4;y++){
   var a = p[x][y];
   var phe = "";
   var desc = [];
   if(a.indexOf(al[0]) > -1){
    phe += al[0];
    desc.push(c[al[0]])
   }else{
    phe += al[1];
    desc.push(c[al[1]])
   };
   if(a.indexOf(al[2]) > -1){
    phe += al[2];
    desc.push(c[al[2]])
   }else{
    phe += al[3];
    desc.push(c[al[3]])
   };
   if(ph[phe]){
    ph[phe].count++;
   }else{
    ph[phe] = {count: 1, desc: desc}
   }
  }
 };
 var phc = Object.keys(ph);
 for(var i = 0;i < phc.length;i++){
  r += ph[phc[i]].desc.join(", ") + ": " + ph[phc[i]].count + "\n";
 }
 return r;
}