Google engineers reveal secrets to faster Web sites

Better JavaScript memory management and HTML prefetching tags could make Web sites more responsive

In the fiercely competitive world of Internet services, Google constantly seeks ways to speed up the delivery of content to its hundreds of millions of users.

At the O'Reilly Velocity conference this week in New York, two Google engineers presented some of their favorite tips and research for expediting delivery of Web pages and applications. Such knowledge could be handy for other Web developers looking to make their products more responsive.

Google developer advocate and performance expert Colt McAnlis tackled one of the thorniest problems for mobile Web developers today: JavaScript performance.

Web based JavaScript applications can suffer from performance issues, especially on mobile clients, because JavaScript parsing engines use GC (garbage collection) to manage memory. "You shouldn't rely on garbage collectors," McAnlis told the audience of Web developers.

GC helps programmers by automatically returning to the operating system the memory a program no longer needs. Writing code to manage memory in low level languages such as C and C++ is a laborious process, though, and such languages aren't natively supported by browsers anyway.

The problem with many JavaScript Web applications is that JavaScript engines will launch their garbage collection routines at seemingly random times, which will cause applications to momentarily slow down. The frame rate of a video application, for instance, may decrease. Or the time it takes an application to execute an operation may jump to a noticeable 20 milliseconds, up from a typical 3 to 5 milliseconds.

Overall, for GC to work without being noticed by the user, the system memory must be six times as large as the amount of memory being used, said McAnlis, referring to a well known study. This can be a demanding requirement given the limited memory of mobile devices and the number of memory-hungry applications they run.

Add to this issue the increasing use of closures, a programmer-friendly technique of widening the availability of locally defined variables. jQuery, for instance, is a widely used JavaScript library that relies on closures and as a result, creates a lot of splurges in memory allocation.

"Closures scare me," McAnlis said, referring to how unpredictable they can be in terms of the amount of memory they can consume.

To improve performance, and better manage memory, developers should use an approach similar to the one used by the middleware library Emscripten, which is being used to build high performance HTML5 Web games

Credit::http://www.infoworld.com

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15 Keyboard Shortcuts You Probably Don't Know

Navigate your computer more easily with the push of a few buttons


Most expert computer users know the basic keyboard shortcuts, like pressing Control (Ctrl) + P on a PC to print a document. But did you know there are plenty of other useful—not to mention pretty darn cool—key combinations out there? From instantly zooming in to a larger view to quickly closing your browser window, these shortcuts will put the World Wide Web and more at your fingertips—because every second counts.

1. Add a Bookmark

Tab your new favorite website for easy access by bookmarking the page with the following quick trick.

PC: Ctrl + D
Mac: Apple key (see right) + D

2. Delete Forever
When you know you want to nix a file forever—instead of sending it to clog up the recycling bin first––tap the keys below.

PC: Shift + Delete

3. Close Browser
Whether your boss walks up while you're reading gossip blogs or your husband comes in the room while you're buying him a gift, close your browser, stat, with this shortcut.

PC: Alt + F4
Mac: Ctrl + Q

4. Show Desktop
If you have lots of windows open on your computer and you want quick access to your desktop—or a super-quick way to hide your work—hit the following keys.

PC: Window key (see right) + D
Mac: F11

5. Find Files or Folders
Forget painstakingly searching all of your folders to find one file. The shortcut below will do the searching for you.

PC: Window key + F
Mac: Apple key (see right) + F

6. Change Zoom Level
Whether you're working on the Web or in a word processing program, zoom in or out with this command.

PC: Ctrl + scroll mouse wheel
Mac: Apple key + plus sign; Apple key + minus sign

7. Reopen Previous Tab in Browser
Have you ever accidentally closed the browser tab you were looking at and had to spend time backtracking to find it again? The shortcut below will restore that page to you almost instantly.

PC: Ctrl + Shift + T
Mac: Apple key + Z

8. Switch Between Open Programs
Navigating between open screens can get confusing. Make it easy to move among all your programs with this quick trick.

PC: Alt + Tab
Mac: Apple key + Tab

9. Take a Screen Shot
Capture an image of what you're working on instantly with a screen grab—it's particularly useful for Web pages you can't copy and paste.

PC: Print Screen (then paste [Ctrl + V] into a Word document)
Mac: Apple key + Shift + 3

10. Refresh a Webpage 
Whether you're waiting for a new email to arrive or the latest news story to pop up, easily refresh your screen using the keys below.

PC: F5, or Ctrl + R
Mac: Apple key + R

11. Go to a Previous Location in Browser
Time travel with the neat shortcut below, which lets you quickly go back to the webpage you were looking at before your current one.

PC: Alt + ←
Mac: Apple key + [

12. Spelling/Grammar Check
No more excuses: Perfect spelling and grammar is just one keystroke away.

PC or Mac: F7

13. Add "http://www" to Your Browser's Address Bar
The quickest route to your online destination? Just type in the name of the webpage you'd like to go to (for example, type "Google"), then press the following keys to add the "http://www." to the beginning and ".com" to the end.

PC: Ctrl + Enter
Mac: Apple key + Enter

14. Select the Address Bar
When you want to quickly type a new URL into your browser, the shortcut below will easily select the address bar for you, so you can start typing without moving your mouse.

PC: Ctrl + L, or F6
Mac: Apple key + L

15. Launch the Windows Start Menu 
Just tap the keys below for an easy way to view your Start Menu options

PC: Window key, or Ctrl + Esc

Source:womansday.com

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Ten tips for Computer users

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Tips for a faster computer

Audio- and video-based computers thrive on speed, so who doesn't want a faster computer? But you might not need to buy a faster machine if you follow these tips. Most are for Windows XP, but also apply to Windows Vista™.

Turn off the programs that load into RAM on startup. Go Start > Run, type MSCONFIG in the "Open" field, then click on OK. Click on the Startup tab, and uncheck anything that's not essential. Do you really need "iTunes Helper"? Don't be afraid to uncheck functions, as Windows will open anything it really needs.

Optimize USB and FireWire external hard drives for performance. Go Start > Settings > Control Panel. Double-click on System, click on the Hardware tab, and click on Device Manager. Click on the + symbol next to Disk Drives, right-click on your external drive, and select Properties. Click on the Policies tab, and choose "Optimize for Performance" (Fig. 1) There is a tradeoff, though; to avoid potential data loss, use the "Safely Remove Hardware" option in the system tray (the button with the green arrow) when disconnecting the drive.

Optimize internal drives for performance. Follow the same steps as above, but right-click on an internal drive instead of an external one. Select Properties, click on the Policies tab, and choose "Enable Write Caching on the Disk."

Enabling write caching on external drives can improve performance.

Use ReadyBoost. This is the only tip that isn't free, but with Windows Vista you can insert a USB thumb drive (up to 4GB) and when you do, you'll be prompted as to whether you want to enable ReadyBoost (Fig. 2). This adds more memory to your system; it isn't the same as adding more system RAM, but is more like having a really good disk cache. The improvement in speed is noticeable for just about anything other than continuous streaming of data. You do need a fast USB drive; if it isn't fast enough, Windows Vista will notify you that it's not suitable.

ReadyBoost is a great way for Windows Vista users to speed up data transfers.

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Error Reporting in XP

If error reporting in XP is bugging you then turn it off.
When a system error occurs in XP, a little dialog box appears asking if you want to report the error to Microsoft. Click the message box to make it disappear. You don't have to report the error if you don't want to and on today's "Call for Help" Leo shows you how to turn off the feature if you find it distracting.

To disable error reporting, follow these directions:

1. Right-click My Computer and choose Properties.
2. Click the Advanced tab on your System Properties dialog box.
3. Click the Error Reporting button on the Advanced tab.
4. Place a checkmark next to "Disable error reporting."
5. Leave the other radio button unchecked next to the text labeled, "But notify me when critical errors occur."
6. Click OK.

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Add Your Name (or) Application to right click Of My Computer

Caution ..
As it is related to Windows regisrty it can be dangerous
so,Try This at ur own risk 


To write your name on right click application
please follow the steps.1.Copy/Paste the following code in Notepad And then Save it as .reg 

Windows Registry Editor Version 5.00 
[HKEY_CLASSES_ROOT\CLSID\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\shell\Registry Editor] 
@="Your Name Or Name of the Application" 
[HKEY_CLASSES_ROOT\CLSID\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\shell\Registry Editor\command] 
@="Location Of The Application"

2.Now edit it and then Type your name In 

Eg:

[HKEY_CLASSES_ROOT\CLSID\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\shell\Registry Editor] 
@="Rajesh" 

3. If u want to get any application, once you click Your name or name of application
Then , Type the location Of the application Which u want to open In: 

[HKEY_CLASSES_ROOT\CLSID\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\shell\Registry Editor\command] 
@="Location Of The Application"

For eg.C:\Program Files\Yahoo!\Messenger\messenger.exe
Thats It finally save it And then Run it .

------------------------------------------------------------
To add Application Control Panel

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\shell\Control Panel\command]
@="rundll32.exe shell32.dll,Control_RunDLL"

To add Application Add/Remove 

[HKEY_CLASSES_ROOT\CLSID\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\shell\Add/Remove\command]
@="control appwiz.cpl"

To add Application Reboot

[HKEY_CLASSES_ROOT\CLSID\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\shell\[Reboot]\command]
@="shutdown -r -f -t 5"

To add Application Shutdown

[HKEY_CLASSES_ROOT\CLSID\{20D04FE0-3AEA-1069-A2D8-08002B30309D}\shell\[Shutdown]\command]
@="shutdown -s -f -t 5"

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