Windump is a Windows port of the famous TCPDump packet sniffer available on a variety of platforms. In order to use this tool on the Windows platform a user must install a packet capture library…

PCAP is the generic file format and concept name for packet capture, not the name of the installable Windows library required by WinDump.

SysPCap does not exist as a real packet capture library; no such tool is part of the standard Windows or network security toolchain.

WinPCap (Windows Packet Capture) is the Windows-specific library that installs a kernel-level packet filter driver and exposes a user-level API for capturing raw network frames. WinDump depends entirely on WinPCap to access the network adapter at a low level, mirroring the role that libpcap plays on Unix and Linux systems.

libpcap is the packet capture library used on Unix and Linux platforms; the Windows-specific equivalent required by WinDump is WinPCap, not libpcap.