There are so many air compressor manufacturers... and there are so many different types and models of air compressors out there.
It's easy to get lost in the dark woods of the air compressor world.. Especially for the home / workshop type compressor, there are a lot of makes and models available to choose from. These are most of the time reciprocating piston compressors. If you use your air compressor only occasionally, there's no need to buy the best compressors. But you get what you pay for!
For the industrial customer looking to buy a compressor, there are a lot less makes and models to choose from. The professional market is dominated by a few big air compressor manufacturers.
It might also be interesting to know that most brands are owned by one of the three big companies: Ingersoll Rand, Atlas Copco and Gardner Denver! Here's a list of air compressor manufacturers that I know of. This list is by far not complete, there are just too many out there. But these are the most popular ones.
Ingersoll Rand air compressors
Ingersoll Rand is a very big company and a mayor air compressor manufacturer. But they don't just ‘do' air compressors. They make air tools, electric tools, lifting tools... but for example also home security systems.
Here's a PDF on their website which should give you a good idea of this company. Ingersoll rand is well known for their high quality, industrial-grade air compressors. They manufacture both reciprocating piston compressors and rotary screw compressors (and other types too).
The compressors they make range from small to very big. From do-it-yourself home compressors to big oil-free industrial compressors. Ingersoll Rand is one of the biggest air compressor manufacturers and produces high-quality air compressors.
Atlas Copco air compressors
Atlas Copco product can be found in almost any industrial company and workshop around the world. They don't just make air compressors; they manufacture all kinds of compressed air tools, electric tools, and much more (including large heavy-duty mining machinery).
Atlas Copco is known around the world for its high quality and great service. Atlas Copco makes all kinds of air compressors. Mostly for the industrial market (big rotary screw compressors), but also for other professional markets (high-end workshop compressors, dental compressors, etc). It's the biggest of all the air compressor manufacturers.
Atlas Copco makes reciprocating piston compressors, rotary screw compressors, scroll compressors, blowers, turbo compressors .. you name it! They are also known for their portable compressors (used on construction sites for example).
Husky air compressor
Husky is a brand exclusively sold at Home Depot (a large chain of stores across America). They are manufactured by Campbell Hausfeld (a compressor manufacturer, read below). Husky compressor pumps used to be made in the USA (they had ‘made in the USA' casted onto the pump). But nowadays this cannot be found anywhere on the pump anymore. I read somewhere they are now made in India, but I don't know if that's true (and don't know if that's a bad thing anyway!)
Campbell Hausfeld air compressor
Cambell Hausfeld is a well-known American compressor manufacturer. Their main markets are the workshop and diy-at-home market (relatively small piston compressors used for powering air tools). They are very popular in the USA
Devilbiss air compressor
Devilbiss is part of Porter Cable. And Porter Cable is part of Black&Decker (together with DeWalt and Devilbiss air compressors).
Sanborn air compressor
Sanborn used to make the popular Black Max compressor range in their factory in Springfield, Minnesota. Since 1994 the company Coleman Powermate bought Sanborn and the Black Max air compressor name. The Sanborn / Black Max compressor range isn't sold anymore. Spareparts and second-hand units can still be bought thougu on several places on the internet.
Coleman Powermate air compressor
Coleman Powermate changed it's name to Powermate Corporation in 2004. Last thing I heard is that Powermate Corporation filed for bankruptcy in 2008. Powermate compressors are still sold on the web, and their website is up and running.. don't know all the details though..
Gardner Denver is a big manufacturer and sells its products under many different brands. The most well-known are their own name Gardner Denver, Champion, and Compair.
Their Gardner Denver range includes reciprocating compressors and rotary screw compressors. Designed for use in industrial environments. Their Champion line is more for the workshop or small factory market, where the compressed air is used for things like air tools. Their Compair range of compressors is also well known and is designed for the industrial market, with both reciprocating and rotary screw compressors.
Compair also sells portable (diesel engine driven) air compressors.
Champion air compressor
Champion is a very well-known manufacturer of air compressors. They produce reciprocating piston, rotary screw and other types of compressors. Their compressors are regarded as good-quality, reliable units. Champion is part of Gardner Denver. It looks like it's their line for the ‘workshop/small factory market'.
DeWalt caries their own range of portable compressors for the contractor market. They are all small portable compressors, with either an electrical motor or diesel engine. DeWalt is part of Black&Decker.
Emglo air compressor
Emglo is a small company producing two models of air compressors for contractors who use them on-the-job on construction sites. Their compressors are made for use with small air tools like nailers.
Craftsman air compressor
Craftsman makes all kinds of power tools, including air compressors. Their main focus is on the DIY and contractor market. Their compressors are small, portable and relatively cheap.