Windows supports an Internet Control Message Protocol (ICMP) to determine whether or not a particular host is available. http://www.delphi-central.com/tutorials/icmp-ping.aspx
This Delphi source code shows how the GradientFill function can be used to add smooth shading to a triangle or rectangle. http://www.delphi-central.com/tutorials/DelphiGradientFill.aspx
NTFS file system 5.0 provides an implementation of IPropertySetStorage interface for files on an NTFS volume. http://www.delphi-central.com/tutorials/File_Summary.aspx
For Word or Excel documents (compound files) the summary information is a part of document itself. http://www.delphi-central.com/tutorials/File_Summary_Info.aspx