Most anti-virus utilities are powered by a large virus signature database that needs to be constantly updated to help them identify known viruses. The database keeps growing as new viruses are released at an ever-increasing rate. Also these utilities are incapable of recognizing a newly released malware since there is no match in the database.

Prevx is based on behavior-based detection as its primary concept and is very good in doing that job.

Advantages of Prevx:

* Download size of 800 KB compared to the 20 MB size of other malware utilities
* Instantaneous installation and ultra fast scan
* Cloud-based malware detection
* Highest malware blocking score

How does Prevx achieve this?

As mentioned earlier, Prevx doesn’t rely on predefined signatures, it rather looks for patterns of suspicious behavior. In addition, it takes the local age of the file and its distribution index into account, before flagging it as a malware. Newer files are under higher suspicion than a file that has been around for a while. Similarly, a widely distributed file is considered benign compared to one that is found on a handful of computers. Prevx confirms this by checking its online database.

On my computer Prevx took around 30 sec to download and performed a learning scan in 5 minutes. It will clean up low risk adware for free, but anything serious has to be cleaned up by purchasing a license key.

One drawback of Prevx is it needs to contact the database during scan and will not work in offline mode.

You may find more details about this anti-malware utility on their site www.prevx.com.

Going through the number of times WCAG is mentioned in Twitter and blogs, I find that it has not got the publicity it deserves. Most developers tend to think of accessibility as a luxury they cannot afford. Consequently it finds its place way down in their priority list. However, as we shall see, making a site accessible will not cost you a lot. And accessibility is not only aimed at addressing the needs of disabled, but people who use text browsers, low resolution monitors etc. Thus if your site is designed with accessibility in mind, you will surely see more traffic to your site.

World Wide Web Consortium (W3C) is responsible for developing Web Content Accessibility Guidelines (WCAG) documents. The first version, WCAG 1.0, was published in May 1999. The latest WCAG 2.0 was released on 11^th December 2008. The primary intent to publish these documents was to make web content easily accessible to everyone irrespective of any disabilities. WCAG 2.0 is designed in such a way that it is simpler and easier to understand for the web developer community. The document is built on four foundational principles. Then, there are few guidelines provided under each principle. Each guideline is challenged by different testable success criteria. Satisfaction of all these criteria will make the web site conform to WCAG. Let us go through the four principles in brief.

Perceivable

The first principle implies that any content that is displayed on the website must be perceivable. The dictionary meaning of the word perceivable means ‘To achieve understanding of’, ‘To become aware of directly through any of the senses, especially sight or hearing’. In our context, it means that anyone who accesses the web for content should be able to apprehend the information that is presented.

There are four guidelines furnished to illustrate this principle. The first two coerce to provide text alternatives for non-text content and time-based media. This would enable the user to enlarge or render in whatever tactile form as needed. The third guideline focuses on the structure and presentation of the content. A simple design that complies to the standards will reduce the complexities when there is a requirement to extract content and present to debile users. Sometimes distinguishing foreground information from background can become difficult. The fourth guideline helps avoid this conflict and focuses on making information distinguishable. Success criteria are determined on color, contrast, background audio, text images and many more.

Operable

The second principle deals with the operability of the user interface components. Users can come across situations where they are not able to interact with the content due to issues in links, user controls and other navigation.

The first guideline under this principle recommends making all the functionality of the content available from a keyboard. This does not outweigh the use of mouse and other interfaces. On the contrary, it means that complete dependence on these devices must be forgone. The guideline also cautions of keyboard traps and advices methods to keep the user away from them. The other guidelines focus on ensuring that the users will be able to complete the tasks required by the content with their own individual response times. For every time limit automatically set by the content, it requires the user to have options to turn it off, adjust and also extend the limit. They also caution the design about seizures mainly occurring due to excessive use of Flash. The last guideline recommends helping the users in their navigation to find content. There are 10 success criteria listed to check whether a user is properly guided.

Understandable

Understandability is the next issue the document addresses. The principle mainly targets the people in the lower part of the intellectual group. It compels the developer to make the content easily available in predictable ways and also help the user avoid and correct mistakes.

The first guideline stresses on making the content readable and understandable. Success criteria are set on languages, abbreviations and pronunciations. It also speaks about restricting unusual words or phrases including idioms and jargon. The other guidelines show light on making the pages predictable and providing assistance to the user in mistake-prone sections. Using instructional labels and help pages can assist the user in different areas.  Detecting errors and reporting immediately, as and when the user is inputting information is also a better method of assistance. These together form the success criteria for this principle.

Robust

The last principle is the most important of all the four. It checks the robustness of the content. Accessibility by user agents is checked here. There is only one guideline and it speaks about the compatibility of the content with the current and future technologies. Avoiding deprecated features of W3C technologies makes the site more compatible. Success criteria are designed for custom user interfaces to check compatibility.

Adhere to the guidelines suggested in WCAG 2.0 will bring in more traffic. Therefore it is essential from the developers’ point of view to know these standards and make them a part of our work.

Link for further study:
http://www.w3.org/TR/WCAG20/

Are you a busy Internet professional or website owner who’s finding it difficult to sign into several micro blogging accounts to post your business topics? It can be quite a tedious and time-consuming process to log into each of these accounts and individually post your news.

SPNBabbble solves all that for you. With an SPNBabble account, all you need to do is enter a single posting and voila! It gets published simultaneously in Twitter, Facebook, Plurk, Tumbrl, and Friendfeed. You will of course need to be a member in all these communities.

Well, doesn’t that make social media networking a lot easier for you? What’s more, many of SPNBabble’s features are similar to Twitter. So Twitter users are going to find it quite easy to operate this plugin.

SPNBabble also has other features, which are:

• SMS messaging
• Direct messaging
• IM message
• Hash tag usage
• Search
• Groups

SPNBabble is specially developed for website owners, web masters, web developers, web designers and business professionals. An offshoot of SiteProNews, this site is in the Jayde Online Network and deployed using Laconica software.

More features are planned in the future to give connectivity to other micro blogs. With this, SPNBabble is surely on its way to becoming a hot favorite among web publishers!

Google has added some new features to its already existing features which would make life simpler for its users. Google’s engineers are working round the clock in Google Labs, adding new features to make Gmail more popular and ahead of its competitors. One feature which is very useful is importing your emails and contacts from other accounts to Gmail.

Gmail users can easily import all their emails and contacts from Hotmail, Yahoo, or AOL accounts. All a user needs to do is enter his Webmail account details (user name and password) into Google’s service and over the next 24 to 48 hours, all his emails and contacts will be automatically imported to his Gmail account.

Google now also lets you test drive Gmail. The company offers a 30-day test-drive mode for users to decide whether they like Gmail or not. The feature, presently available to new users, is likely to be extended to current users soon.

Google has also added a search widget in Gmail, which enables users to search the web without opening a new browser.

The new feature shows a search box onto the left side of Gmail inbox. When a user types in a search, a window (like a chat window) appears at the bottom of the screen with search results.

These are some of the new features that Google has added in its Gmail service. To know more about the latest features in Gmail, just visit Google Labs where a whole lot of gadgets and features await you.

A cool new e-reader called Cool-er has arrived in the market. With its advent, digital reading will become a bit more affordable at $250.

Cool-er, as its name suggests, makes reading cooler.

Cool-er will have to face massive competition from the hugely popular Amazon Kindle. Kindle has been dominating the digital reading market for so long and a lot of users have grown very comfortable with it. The heavy price tag of Kindle is its major drawback plus its weight which is slightly more than 10 ounces.

The main advantages that Cool-er offers are:

• It is lightweight – weighs only half as much as the competition.
• It comes in 8 pretty colors.
• It uses power only for “page turns” which means that a single charge lasts for 8000 pages.
• It can read JPEG, PDF, TXT documents or any EPUB formatted eBook.
• Users can vary the size of text to provide maximum ease of reading.
• It uses an E Ink VizplexTM screen that makes it readable at any angle and even in direct sunlight.
• It contains the added bonus of MP3 features.

The success of this new product in the market will depend upon how users are going to accept it, depending on its features and ease of use.

For those of you who are wondering what Cool-er looks like, take a look here.

Many newcomers to the programming field would be confused with the two terms – ASP and ASP.NET.  If you are one among them, here are some points that would help you to understand the differences between the two:

1. ASP.NET supports different languages like C#, VB etc., whereas ASP is a scripting language that supports VBScript, JavaScript.
2. ASP.NET is easy to debug (i.e. solve errors).
3. ASP.NET is a compiled language, which means it’s faster compared to ASP.
4. ASP.NET has two separate files for presentation logic and business logic, whereas in ASP both presentation and business logic are in the same page. This reduces the complexity in ASP.NET.
5. The size increases in ASP.NET because to execute the ASP.NET page, you need .NET framework installed. ASP on the other hand, doesn’t require it. (You just need to write your code in Notepad and execute it).
6. ASP is totally free.
7. ASP.NET is an object-oriented language. So with the use of classes, interface etc. you can reduce lines of code and the performance increases.
8. In ASP.NET, you can make your own user controls to access it through pages.
9. In ASP.NET, for security we have CAS (Code Access Security), which helps you to view only particular portions of the code.

That summarizes the differences between the two. I hope this article has helped you understand the two technologies better.

Have you ever thought of bringing down your favorite or most used web application to desktop?

Now you can! On May 05 2009, Mozilla brought out their new application MOZILLA PRISM. The engineers at Mozilla labs were able to bring up version 1 of Mozilla Prism, which was earlier known as WebRunner.  Although the basic theory behind Prism is SSB (Site-Specific Browsers), it is also like a normal browser (similar to Firefox as it comes from the same hood of Mozilla). The only difference between Prism and a normal browser is that, unlike a normal browser, Prism is for a specific site or web application. It therefore doesn’t show up the normal menus, toolbars or any other stuff that a normal web browser provides.

The best thing about Prism is that you can now run your favorite web application from desktop, as you would do for a normal software application. With Prism, you don’t need to run the browser to read your email or check the latest in your favorite social networking space. All you have to do is install the standalone application of Mozilla Prism to your computer, set up the basic configurations (like the web address of your web applications) and you are ready to go!

After the initial setup you can place the shortcut for the web application on the desktop itself, instead of having to type the same address over and over again into your web browser.

Besides all the above, if you configure your web mail with Prism and minimize it to the notification area of your desktop, it will notify you whenever you get a new email…!!

Sounds cool, doesn’t it? You can get your piece of Prism from here: Mozilla Prism.

Do try it out and post your comments about Prism.

Replication has now become an essential feature for most MySQL users. The good news I can share at the same time is that the working and implementation of this concept is also less complicated. It involves a minimum of 2 servers: a master and a slave (in most cases). The slave makes use of the binary logs created by the master to update its database thereby keeping both of them in exact synchronization.

Issues Leading to the Need of Replication

Heavy Load:

Lets consider a website with an exponentially increasing number of users regularly. There will arrive a state in which the single database server could no longer handle the load anymore. If the server receives more number of read queries rather than write queries (which will be the normal case for most of the websites) then, the best choice will be to adopt replication into the current architecture. Here, the read queries refer to SELECT statements and the write queries refer to INSERT, UPDATE and DELETE statements.

Now I am going to explain how replication solves the issue of heavy load. When the concept of replication is implemented we will be having more than one server. Among these servers, the one named as master will receive queries related to write and make changes to its database immediately. Consequently, when the binary log is updated, the slaves update their database reading from the log files. The slaves on the other hand receive all read queries. Depending on the number of queries received, the number of slaves can be increased or decreased. Now by using any scheduling algorithm (Round Robin is an example), we can effectively load balance the incoming read queries to different slave servers so that all of them get equal workloads.

Backup: Anytime and Without Client Disturbance

During backup requirements, we normally stop MySQL or lock the read queries to get an exact backup. This may sometimes result in the annoyance of the clients who access the website during the process. Although there are a few clever techniques with which you may do this without the notice of the clients, things become very simple with replication.

The slaves always remain in exact synchronization with the master. In other words, the slaves will have another copy of the entire repository that the master processes. And hence backing up of a slave is similar and as good as backing up of the master. Also the presence of slaves as exact replicas will in most cases help avoid the need for backup of the master. This is because we always have the slaves as a spare in case of any misfortunes to the master.

Distribution of Data Without Respect to Distance:

Next issue I am to focus on deals with distributing copies of data in various locations that are geographically very apart which is not a trivial task. But the replication factor gives the flexibility that we require to make it trivial.

The master provides no errors even if the slave remains disconnected for some time. So in spite of the poor connection and other factors that may influence the link between the different destinations, a synchronized copy of the master can be made to exist in a geographically distant region.

Architectures of Replication

There are a few rules that I recommend to be kept in mind to better understand the different architectures.

• There needs to be a unique server ID for every slave
• There can be many slaves for a master
• There can be only one master for a slave
• Slaves can also function as masters

Master: Slave

This architecture best suits an environment, which has low number of write queries and high number of read queries. Effective load balance can be achieved by spreading the workload among the different servers. Here is an illustration.

Dual Master:

This kind of architecture is particularly useful when servers are geographically far apart. Although during interruptions, neither will have access to their data both will catch up from each other when the connection is reestablished. An extension of this architecture will be to have a slave on either side that is also diagrammatically shown below.

.

Pyramid:

In a large organization where there is diverse distribution in a hierarchical manner, a possible architecture like this will be the best suit. There is no necessity to configure every slave with the master as the slave above in the hierarchy can act as their master.

Although replication solves problems, it demands so much precision, which if not taken care of, can even result in the crash of the master database. Slaves are not always in synchronized state with their master. But with proper monitoring systems this can be detected. The concept of replication is provided by MySQL and can definitely improve overall performance if dealt with proper caution.