Here's what I use - it works for me, but I certainly don't use the full set of jquery methods. However, I think it covers most of the gaps.

/*
* Array Functionality
* script: array.js
* for: browsers not implementing the full array functionality of ECMA262-3
* by: liorean
* thanks to: beetle
*/

if(typeof Array.prototype.copy == 'undefined')Array.prototype.copy = function(a) {
   var i = 0, b = [];
   for(i; i < this.length; i++)b[i] = (typeof this[i].copy != 'undefined') ? this[i].copy() : this[i];
   return b}
;

if(typeof Array.prototype.concat == 'undefined')Array.prototype.concat = function(a) {
   var i = 0, b = this.copy();
   for(i; i < a.length; i++)b[b.length] = a[i];
   return b}
;

if(typeof Array.prototype.pop == 'undefined')Array.prototype.pop = function() {
   var b = this[this.length - 1];
   this.length--;
   return b}
;

if(typeof Array.prototype.push == 'undefined')Array.prototype.push = function() {
   var i = 0, b = this.length, a = arguments;
   for(i; i < a.length; i++)this[b + i] = a[i];
   return this.length}
;

if(typeof Array.prototype.shift == 'undefined')Array.prototype.shift = function() {
   var i = 0, b = this[0];
   for(i; i < this.length - 1; i++)this[i] = this[i + 1];
   this.length--;
   return b}
;

if(typeof Array.prototype.slice == 'undefined')Array.prototype.slice = function(a, c) {
   var i = 0, b, d = [];
   if(!c)c = this.length;
   if(c < 0)c = this.length + c;
   if(a < 0)a = this.length - a;
   if(c < a) {
      b = a;
      a = c;
      c = b}
   for(i; i < c - a; i++)d[i] = this[a + i];
   return d}
;

if(typeof Array.prototype.splice == 'undefined')Array.prototype.splice = function(a, c) {
   var i = 0, e = arguments, d = this.copy(), f = a;
   if(!c)c = this.length - a;
   for(i; i < e.length - 2; i++)this[a + i] = e[i + 2];
   for(a; a < this.length - c; a++)this[a + e.length - 2] = d[a - c];
   this.length -= c - e.length + 2;
   return d.slice(f, f + c)}
;

if(typeof Array.prototype.unshift == 'undefined')Array.prototype.unshift = function(a) {
   var b;
   this.reverse();
   b = this.push(a);
   this.reverse();
   return b}
;

if (typeof Function.apply != 'function') {
   Function.prototype.apply = function(o, a) {
      o.____apply = this;
      switch(((typeof a == 'object') && (a.length)) || 0) {
         case 0 : o.____apply();
         break;
         case 1 : o.____apply(a[0]);
         break;
         case 2 : o.____apply(a[0], a[1]);
         break;
         default : o.____apply(a[0], a[1], a[2]);
         break;
         }
      }
   ;
   }

Your mileage, as they say, may vary...

I doubt this is major. IE 5.0 was released seven years ago or some such. It's market share is next to nothing now.

There were several attempts to this, which ended with this message by Alistair Potts:

"OK, I've done some more work on this and it's a hopeless task. While you

can rewrite the pseudo-apply function to work, IE5.0 can't seem to work

out the length of the jquery object correctly.

But even if you get that working, IE5.0 doesn't support rudimentary

RegExp, e.g. "?=w".

It's time to give up. It's beyond a plugin to fix. John, if you read

this, don't waste your time with an IE5.0 plugin, there is more

important stuff to address!"