Per CVE-2002-1603: GoAhead Web Server 2.1.7 and earlier allows remote attackers to obtain the source code of ASP files via a URL terminated with a /, \, %2f (encoded /), %20 (encoded space), or %00 (encoded null) character, which returns the ASP source code unparsed.
Foo WebServer turns up in a number of interesting places, like S2 and Linear eMerge door access systems and Rockwell Automation AB ControlLogix controllers.