It also should be useful for checking the specifications for an existing product's performance. When I am designing, I don't have time to page backwords and forwards through 'pretty pictures' to get to the posted specifications. As these are links to files within URLs, they probably will change more often than the actual address of the company-please inform me if they become stale. A few manufacturers require registration for use. It may be necessary to download an Adobe Acrobat viewer.
Most data listed is for current or preferred parts.
Don't expect manufacturers to expend the effort to post archival data about obsolete parts. Any new site information is welcome.