<p>Are there other possibilities besides IIS for hosting web sites and web services based on ASP.NET, which are recommended by Microsoft for small-scale environments?</p>

Ohad has a tutorial on getting it to run on apache:
asp.net on apache
.  I'm not really sure how well it runs but it works.  I don't think Microsoft recommends anything other than IIS, but why would they.  For most small scale uses a Windows Server will have everything a small site needs already packaged in.  I'm not sure why you need to find alternatives unless you don't have a windows server available, in which case, the apache port should work for you.