Zamboni

While Zamboni is now a colloquialism for an ice resurfacer, the name Zamboni is actually a registered trademark of Frank J. Zamboni & Co, Inc..

An ice resurfacer appears in almost every single NHL game prior to and after a match, and also resurfaces during both intermissions. The Zamboni is a big machine designed to resurface the ice surface of the rink. In most cases, if not all, The Zamboni will resurface the ice in a circular manner. It starts from one end of the rink and resurfaces half of the rink, then does the other half. The Zamboni obviously will be advertising the home team, as it is owned by the arena, or owners of the hockey club.

The Zamboni drags an attached conditioner behind it as it cleans the ice. There's a squeege at the end, which removes unwanted blemishes on the ice. What it's doing in front of the squeege is shaving the ice and collecting the shavings by cycling them through a vaccum-like system. While it does this, it releases hot water on the ice to freeze into a smooth surface for the next period of the NHL game. You can see this in XBOX's NHL '08 and can play a mini-game during intermissions in NHL 2

There's a cheat in NHL '99 (PC) which is activated during gameplay when you type in the code, 'Zamboni'. It enables a zamboni to clean the ice while the game's still being played. When you use this cheat it's supposed to increase the player's speed and acceleration (you know, because of the new ice), but the difference isn't too noticeable.

On the Xbox 360 version of NHL 2K9, you'll unlock an achievement for passing the Zamboni mini-game, which doesn't actually require all of the ice to be covered although you will need to cover most of it (hit a percentage somewhere  in the 90s, to be safe). The percentage of ice covered is displayed in the corner of the screen, so it's fairly easy to tell how you're progressing.

In total there are 30 NHL Zamboni's in the older NHL games such as NHL'99 (PC), NHL '00 (PC), NHL '01 (PC), etc.
The detail in the Zamboni's have gotten better since EA Sports' older make of NHL '99-03 (for any system). For instance, In NHL '99 PC, the zamboni is just moving around the ice. In NHL '04 PC, the zamboni moves aropund the ice and the wheels move, the brush spins, etc. Now in NHL '08 PC, the zamboni detail is better than the previous games, XBOX Zamboni's have much better detail than all the other versions, at the time.