Thx for your answers guys, it is a friend of mine who got it as an attached file to a travel/journey he ordered. Sort of a travelplan I suppose, he says that it showes the excel icon, but he can't open it in excel.
Like jakesnake I found microworlds too
Unfortunately we don't know what system you firend is running - I also found this Important Information For All MicroWorlds Pro Owners
Recently Microsoft made changes to Internet Explorer. As a result of these changes, the MicroWorlds Pro WebPlayer Plug-in (version 2.17 and earlier) will not work with IE 6 or IE 5.5 with Service Pack 2.
There is more here:
_http://www.ask.com/main/metaAnswer.asp?t=ai&s=a&MetaEngine=directhit&en=te &eo=3&o=0&frames=True&url=http%3A%2F%2Fwww%2Emicro worlds%2Ecom%2Fwebplayer%2Factivex%2Ehtml&ac=6&adc at=tech&pt=LCSI+%2D+Project+Library&dm=http%3A%2F% 2Fwww%2Emicroworlds%2Ecom%2Fwebplayer%2Factivex%2E html&io=0&qid=3AE6C6F95B69284AB7F40816C15EC8C1&bac k=ask%3Dwhat%2Bis%2Bfile%2Bextension%2Bmwz%26o%3D0 %26qsrc%3D1%26meta%3D1&ask=what+is+file+extension+ mwz&dt=030203083919&amt=&pg=1&qsrc=1