Would it be legal to make compatible bricks which are called differently? If so, why is nobody doing it? If not, there is your answer why LEGO is expensive; to quote the dude from Idiocracy, "ohhh, I like money".
* A Lego compatible case, that can accept an Arduino board.
* A range of Lego compatible sensors and actuators
* Other components following the theme of integrating open-source with Lego.
* and so on...
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Edit: formatting
I started the Bitbeam project because I was prototyping some things in LEGO, but when it came time to figure out how to make many of them, I wasn't too excited about the cost of LEGO... but I was happy with my LEGO design. So I decided to port LEGO dimensions to materials that are easier and cheapier to source myself.
Some that are blessed by Lego: http://www.hitechnic.com/products
... and some that are not: http://www.mindsensors.com/ http://www.techno-stuff.com/
Also, this exists, targeted at the education market: http://www.vernier.com/products/interfaces/bta-nxt/
They did, and this was actually pretty hypocritical of lego because lego started out copying a UK design, the "Kiddicraft Self-Locking Building Bricks".
On another note, the lego brand is usually explained as 'play well' in Danish, but this is much more along the lines of 'goods to play with' (like in the German spielzeug or the Dutch speelgoed). Of course that doesn't isn't nearly as good marketingwise hence the 'play well' myth.
It's "legetøj" in Danish though, so I'm not sure how that becomes Leg go'. I've never heard "godt" in danish used for "goods".
Source?
While I don't speak Dutch, speelgoed literally translates to "toys". Several google searches on the etymology of leg godt didn't turn up any alternative definitions or connotations.
IOW, the parent is correct that "speelgoed" pretty much means "goods to play with". I have no knowledge about the Danish leg godt story, though.
Source: Native Dutch speaker