Temas tecnicos sobre IP

Multi-threaded refers to an application that can have multiple
blocks of code (or threads) executing simultaneously.
Thread-safe applies to libraries and means that two or more
threads a multi-threaded application can access a thread-safe
library with at the same time without interfering with each others
changes to the library or thier memory spaces.
Según aparece en difference between thread-safe and multi-threade.
php

The luhn algorithm is a simple checksum formula used to check the validity of credit card numbers. It works like this:
First every second digit, beginning with the second to last and moving towards the left is multiplied by 2. If the result of doubling any of those nubmers is is 10 or more, its digits [...]

Forma rápida con JavaScript

var ancho= Screen.width;
if(ancho<800)
{document.write(”<link type=’text/css’ rel=’stylesheet’ href=’css4Chico.css’ />”);
else
{document.write(”<link type=’text/css’ rel=’stylesheet’ href=’css4grande.css’ />”);

Existen formas mas elegantes como la mostrada en http://particletree.com/features/dynamic-resolution-dependent-layouts/