Design/CPN is a graphical tool supporting the use of Hierarchical Timed Coloured Petri Nets. The Editor supports construction, modification, and syntax check of CPN models. The Simulator supports interactive and automatic simulation of CPN models. The Occurrence Graph Tool supports construction and analysis of occurrence graphs for CPN models (also known as state spaces or reachability graphs). The Perfomance Tool supports simulation-based performance analysis of CPN models.
dhcpcd is an RFC2131 compliant DHCP client. It is fully featured and yet lightweight: the binary is 60k as reported by size(1) on Linux i386. It has support for duplicate address detection, IPv4LL, carrier detection, and a merged resolv.conf and ntp.conf for which other DHCP clients require third party tools.
Dia2Code is a small utility to make code from a Dia Diagram, and eases the programmer's work by generating the structure of the classes in an Object Oriented language (like C++ and Java) from a graphical representation of them (a la Dia Diagram). It can generate code for many languages.
Diald manages network links, particularly on-demand links such as dial-up SLIP or PPP. It can also be used to manage and/or monitor any network interface. Diald monitors traffic on the link and makes intelligent (and highly configurable) decisions as to when the link should be brought up or taken down. The included control program, dctrl, runs on any system with Tcl/Tk (yes, even Windows) and allows diald to be controlled and monitored remotely.
dict_pgsql is a dictionary for the mailer postfix. It is able to get all virtual users out of a postgres database; this is very helpful if you have a large number of users who make updates on their aliases quite often. You don't have to extract all the values into system files; the entries will be fetched directly from the database.