Let’s use the Fibonacci sequence as an example. I wrote six different versions to calculate it. Obviously the naive, recursive way of calculating it is the slowest, but that is where similarities between browsers end. Internet explorer seems to be faster at looping than rounding numbers. And Chrome seems to favor local variables over global ones so much it doesn’t mind doing a lot more calculations.

Update: This seems to be fixed in Explorer Platform Preview 1.9.7766.6000.

As I’m still learning ASP.NET MVC, my solution may not be the optimal one.

Create a custom model binder that will only react differently to double values.

using System;
using System.Globalization;
using System.Web.Mvc;

namespace NerdDinner.Helpers {
  public class CustomModelBinder : DefaultModelBinder {

    public CustomModelBinder()
      : base() {
    }

    public override object BindModel(ControllerContext controllerContext, 
      ModelBindingContext bindingContext) {
      
      object result = null;

      // Don't do this here!
      // It might do bindingContext.ModelState.AddModelError
      // and there is no RemoveModelError!
      // 
      // result = base.BindModel(controllerContext, bindingContext);

      if (bindingContext.ModelType == typeof(double)) {

        string modelName = bindingContext.ModelName;
        string attemptedValue = bindingContext.ValueProvider[modelName].AttemptedValue;

        // Depending on cultureinfo the NumberDecimalSeparator can be "," or "."
        // Both "." and "," should be accepted, but aren't.
        string wantedSeperator = NumberFormatInfo.CurrentInfo.NumberDecimalSeparator;
        string alternateSeperator = (wantedSeperator == "," ? "." : ",");

        if (attemptedValue.IndexOf(wantedSeperator) == -1 
          && attemptedValue.IndexOf(alternateSeperator) != -1) {
          attemptedValue = attemptedValue.Replace(alternateSeperator, wantedSeperator);
        }

        try {
          result = double.Parse(attemptedValue, NumberStyles.Any);
        }
        catch (FormatException e) {
          bindingContext.ModelState.AddModelError(modelName, e);
        }

      }
      else {
        result = base.BindModel(controllerContext, bindingContext);
      }

      return result;
    }
  }
}

Change the DefaultBinder in Global.asax.

void Application_Start() {
  //[SNIP]
  ModelBinders.Binders.DefaultBinder = new CustomModelBinder();
}

<%
// prevent caching (asp classic jscript)
Response.CacheControl = "no-cache";
Response.AddHeader("Pragma", "no-cache");
Response.Expires = -1;
%>

<%
' prevent caching (asp classic vbscript) '
Response.CacheControl = "no-cache"
Response.AddHeader "Pragma", "no-cache"
Response.Expires = -1
%>

<?php
// prevent caching (php)
header('Cache-Control: no-cache');
header('Pragma: no-cache');
header('Expires: ' . gmdate(DATE_RFC1123, time()-1));
?>

// prevent caching (C#)
//Response.AddHeader("Cache-Control", "no-cache");
//Response.AddHeader("Pragma", "no-cache");
//Response.Expires = -1;

Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Cache.SetNoStore();
Response.Cache.SetExpires(DateTime.MinValue);

More information here: How to prevent caching in Internet Explorer

Compare for yourself:

• silverlight vs javascript (unchanged original)
• silverlight vs flash (js delegates all logic to flash, silverlight code unchanged)

<%@LANGUAGE="JAVASCRIPT" CODEPAGE="65001"%>
<%

function getData(connectionString, sql){
    var result = null;
    var adStateOpen = 1;
    var connection = new ActiveXObject("ADODB.CONNECTION");
    try{
        connection.Open(connectionString);
    } catch(e1){
        return null;
    }
    if (connection.State !== adStateOpen) {
        return null;
    }
    try{
        var recordset = connection.Execute(sql);
    } catch(e2){
        return null;
    }
    if (!recordset.EOF) {
        result = recordset.GetRows().toArray();
        recordset.Close();
    }
    recordset = null;
    connection.Close();
    connection = null;
    return result;
}


function writeCsvHttpHeaders(filename){
    Response.ContentType = "text/csv";
    Response.Charset = "utf-8";
    Response.AddHeader("Content-Disposition", 
            "attachment; filename="+filename+".csv");
}

function writeXlsHttpHeaders(filename){
    Response.ContentType = "application/vnd.ms-excel";
    Response.Charset = "utf-8";
    Response.AddHeader("Content-Disposition", 
            "attachment; filename="+filename+".xls");
}

function getXlsStart(){
    return ""
    + "<html>\n"
    + "<head>\n"
    + "<meta http-equiv=\"Content-Type\" "
    + "content=\"text/html; charset=UTF-8\">\n"
    + "<style type=\"text/css\">\n"
    + "html, body, table {\n"
    + "    margin: 0;\n"
    + "    padding: 0;\n"
    + "    font-size: 11pt;\n"
    + "}\n"
    + "table, th, td { \n"
    + "    border: 0.1pt solid #D0D7E5;\n"
    + "    border-collapse: collapse;\n"
    + "    border-spacing: 0;\n"
    + "}\n"
    + "</style>\n"
    + "</head>\n"
    + "<body>\n"
    + "<table>\n"
    + "";
}

function getXlsEnd(){
    return ""
    + "</table>\n"
    + "</body>\n"
    + "</html>"
    + "";
}

function csvEscape(val){
    if (typeof val === "number") {
        return val.toString(10).replace(".", ",");
    } else if (typeof val === "string") {
        if (val.indexOf("\"") !== -1) {
            return "\""+val.replace(/"/g, "\"\"")+"\"";
        } else if (val.indexOf(";") !== -1) {
            return "\""+val+"\"";
        } else {
            return val;
        }
    } else if (val === null) {
        return "#NULL#";
    } else if (val === undefined) {
        return "#UNDEFINED#";
    } else {
        return "#ERROR#";
    }
}

function writeCsv(filename, data, columnCount){
    writeCsvHttpHeaders(filename);
    // utf-8 BOM (very important for special characters)
    Response.Write("\uFEFF");
    for (var i=0, il=data.length; i<il; i+=columnCount) {
        for (var j=0; j<columnCount; j++) {
            Response.Write(csvEscape(data[i+j]));
            if (j !== columnCount-1) {
                Response.Write(";");
            }
        }
        Response.Write("\n");
        // prevent Response Buffering Limit Exceeded
        if (i % 1000 === 0) {
            Response.Flush();
        }
    }
}

function xlsEscape(val){
    if (typeof val === "number") {
        return val.toString(10).replace(".", ",");
    } else if (typeof val === "string") {
        return Server.HTMLEncode(val);
    } else if (val === null)  {
        return "#NULL#";
    } else if (val === undefined)  {
        return "#UNDEFINED#";
    } else {
        return "#ERROR#";
    }
}

function writeXls(filename, data, columnCount){
    writeXlsHttpHeaders(filename);
    Response.Write(getXlsStart());
    for (var i=0, il=data.length; i<il; i+=columnCount) {
        Response.Write("<tr>");
        for (var j=0; j<columnCount; j++) {
            Response.Write("<td>");
            Response.Write(xlsEscape(data[i+j]));
            Response.Write("</td>");
        }
        Response.Write("</tr>\n");
        // prevent Response Buffering Limit Exceeded
        if (i % 1000 === 0) {
            Response.Flush();
        }
    }
    Response.Write(getXlsEnd());
}

function main(){
    var filetype = Request.QueryString("filetype")();
    var connectionString = "Provider=SQLOLEDB.1;"
    + "Data Source=LAPTOP\\SQLEXPRESS;"
    + "User ID=internal;"
    + "Password=internal;"
    + "Initial Catalog=trees_in_sql";
    var sql = ""
    + "SELECT id \n"
    + ", name \n"
    + "FROM People \n"
    + ";";
    var filename = "filename";
    var columnCount = 2;
    
    var data = getData(connectionString, sql);
    if (data !== null) {
        Response.Clear();
        if (filetype === "csv") {
            writeCsv(filename, data, columnCount);
        } else {
            writeXls(filename, data, columnCount);
        }
    } else {
        Response.Write("Error, no data found");
    }
    Response.End();
}

main();

%>

Resources: