What web 2.0 is ? How can i make web 2.0 ?

Many new webmaster / developers / designers have a question in mind that may be like:
What web 2.0 is ?
How can i make web 2.0 ?
..etc etc

Web 2.0 is the future, it is used mostly to create web applcations.

In terms of design using =>
- glossy
- gradients
- bright colors (most of the time, not always)
- diagonal lines
- bubbly

In other words =>

DoubleClick --> Google AdSense
Ofoto --> Flickr
Akamai --> Bitorrent
mp3.com --> Napster
Britannica Online --> Wikipedia
personal websites --> blogging
evite --> upcoming.org and EVDB
domain name speculation --> search engine optimization
page views --> cost per click
screen scraping --> web services
publishing --> participation
content management systems --> wikis
directories (taxonomy) --> tagging ("folksonomy")
stickiness --> syndication (RSS or Atom)


Table less design also come under web 2.0
Using REST API is also web 2.0

Example of such sites are :

Google Adsense
Wikipedia
Orkut
LinkedIn

This was in my simple words you may read more about web 2.0 here

If you want to add some thing more just comment on the blog.

Closely coupled code Vs Loosely coupled code

I saw many of the users don't know meaning of this and there differences. I would like to post it here for the users.
=>

Basically, closely coupled code means that one part of the code is strongly dependent upon another part. This means that any change in one part may have unforeseen/unwanted effects on another part.

Ideally, loosely coupled code allows for separate parts of the application to not have that strong dependency on other parts. This has a number of benefits, such as keeping bugs isolated to one area of the code (instead of having cascading effects throughout the code) and it makes it easier to re-use portions of the code.

e.g. when you use "global" within a function, you then closely couple that function to whatever it is that initially defines that variable. If for some reason that other part of the code is changed to rename that variable or do things you didn't anticipate, it might break that function. Likewise, you might not realize that the function is doing things to that variable, causing unforeseen bugs in the application. And of course it becomes difficult to re-use such a function in another context if that same variable name does not exist there and have the same meaning/usage.

<img> tag problem while XSLT transformation

Problem: When i use < img src="" /> tag in XSLT i face problem while transforming, normally i get Blank page or some unkown error.

Answer:

Normally when you use <img> tag, there may be various reason. Like When image tag is written you must use / at the end <img src="" />

Also when you want to use some value select into the tag you get white space. Normally you might be doing something like this.
<img src="<xsl:value-of select="node1/node2" />" />

Actually what you have to write is <img src="{node1/node2}" />
Just remove all that select and just curly braces at start and end. There may be certain times that you may have to write <img src="{node1/@node2}" /> i.e. I mean you have to use @
at the last note.

Using value-of select is not allowed in any tag. the above given procedure is the solution to it.

If you still face the problem you reply to same post. I would edit the post and more solutions.