Salsa is an anonymous community where you can share anything about your job or company. Form big corporations to small startups, it's the perfect place for career related vent, gossip, Q&A or even confess.
Salsa also provides anonymous salary surveys where you can check salaries from similar companies or titles.
The main difference is, we try to build an active community where people can openly discuss any career related topics; while Glassdoor is mostly a company review / salary posting site, with no interactions between users. We also try to be more emotional and personal, and capture the small things in your daily life. Which does not exist in Glassdoor.