Question: I wrote a PHP shell script which include queuing jobs in centOS with 'at' command.
The queue jobs may vary in time and contents which means the system need to keep quite a large number of jobs.
The application logic will also be a bit difficult to setup with cronjob.
Is there a limit in number of queue jobs in centOS or is there any alternative way of queuing jobs?

Answer: 
The book *Pro Javascript Design Patterns* is a great resource:  

<http://jsdesignpatterns.com/>
I would also recommend "Secrets of a JavaScript Ninja" by John Resig. It will be out in July this year and would definitely be an excellent resource.

Else, Douglas Crockford "JavaScript:The good parts" is excellent.