Wiretap, part of the wireshark project, is a library that allows one to read and write several packet capture file formats.

supported formats are:
* libpcap
* sniffer
* lanalyzer
* network monitor
* "snoop"
* "iptrace"
* sniffer basic (netxray)/windows sniffer pro
* radcom wan/lan analyzers
* lucent/ascend access products
* hp-ux nettl
* toshiba isdn router
* isdn4bsd "i4btrace" utility
* cisco secure intrustion detection system iplogging facility
* pppd logs (pppdump-format files)
* vms tcptrace
* dbs etherwatch (text format)
* catapult dct2000 (.out files)
wiretap's shortcomings are: no filter capability and no support for packet capture.