SONAR is how I'm used to spelling it ....
 
                                          Flipper approves
                              
 

Anderton
Style guides say you should never capitalize something that isn't an acronym. But it is:
 
System Optimized for Non-linear Audio/MIDI Recording

                                        Gee I didn't even know that ...Wow ...thanks
                                
 

e.Blue
 However, I don't mind also calling out all of the folks that have it misspelled in their signatures.
 
-e.B

                                    I know exactly how you feel . Yeah me too
 
              
  
Kenny                                                    

tenfoot
I cant say this particular word crime bothers me too much. In the words of a well known peanuts meme:
 
"When comforting a grammar nazi,  I always say softly, "there, their, they're".

Overheard this conversation...    "Jaeat?" "No Jou?"  Translation - "Did you eat?"  No, did you?" 

Anderton
Style guides say you should never capitalize something that isn't an acronym. But it is:
 
System Optimized for Non-linear Audio/MIDI Recording

Current British English style and style guides tend to not capitalise acronyms that are pronouncable as words and regularly are pronounced as words.

Examples being Sonar (first capital because in this context it's a proper noun), radar, laser.

I should have specified product names and such, not words in common usage. The reason for this is companies all want their product names CAPITALIZED, like "DJ Softworks Announces MEGA-MONDO TURBOSOFT DJ."