It is _very_ different. In the case of outsourcing, where companies offer decent local wages in developing countries, it can not be compared to slavery which is the perpetual ownership of a person.
Now with H1B sponsorship, where I've heard rumors of companies taking away passports of their workers, it is very much evil, but not slavery.
As of about 4 years ago software developers in India were making .20 of US counter parts. I was managing a team of 7 and 5 left for higher pay elsewhere. Same has happened in China and other countries. They are not so cheap anymore.
Now with H1B sponsorship, where I've heard rumors of companies taking away passports of their workers, it is very much evil, but not slavery.