Valgrind is a tool that helps you find memory management problems in programs. When a program is run under Valgrind's supervision, all reads and writes of memory are checked, and calls to malloc/new/free/delete are intercepted. As a result, Valgrind can detect problems such as use of uninitialized memory, reading/writing of memory after it has been freed, reading/writing off the end of malloced blocks, reading/writing inappropriate areas on the stack, memory leaks in which pointers to malloced blocks are lost forever, passing of uninitialized and/or unaddressable memory to system calls, and mismatched use of malloc/new/new  vs. free/delete/delete .
GNU gperf is a program that generates perfect hash functions for sets of keywords. A perfect hash function is a hash function and a data structure that allows recognition of a key word in a set of words using exactly 1 probe into the data structure. Output from the GPERF program is used to recognize reserved words in the GNU C, GNU C++, and GNU Pascal compilers, as well as with the GNU indent program.
The VTE library inserts terminal capability strings into a tree of tables, and then uses it to determine if data received from a pseudo-terminal is a control sequence or just random data. The sample program "interpret" illustrates more or less what the widget sees after it filters incoming data.
GAIL is a GTK+ module that provides accessibility support for GTK+ and libgnomecanvas by implementing AtkObjects for widgets in the two libraries. For example, if the module is loaded in a program which calls gtk_widget_get_accessible() for a GtkEntry, an instance of GailEntry is returned. This module is normally used with the atk-bridge GTK+ module from at-spi to allow an assistive technology, e.g a screenreader, to query or drive the program.
Widelands is an economic and military simulation game. The map is shown in parallel perspective with 3-dimensional terrain. Buildings and units are animated. The player controls a tribe. Land is claimed and held by military presence and then used to build an economy to support military expansion and confrontation. The project is a work in progress where much remains to be done; computer players and multiplayer are in very early stages of development. Some features that have already been implemented are exploration, fog of war, sound effects, background music, adjustable simulation speed, a few tutorial campaigns, translations to several languages, and a map editor.
This is a driver for network scanning using a Dell 1600n Printer/Scanner/Fax/Copier. It is implemented as a Perl script. In principle, this means that it should be cross-platform. It has been tested under Linux (Debian and Gentoo) and Windows (NT4 with Cygwin) on Intel. Supported formats are TIFF and JPEG. With an external program (e.g. ImageMagick convert), PDF is supported.
Asimulator is a simulator for intelligent agents, useful to practice search algorithms, in AI courses, or for fun. The agent's goal is to understand precepts and respond with actions in a virtual world (consisting of a grid up to 129x129) to maximize a score. The simulator opens a socket, so any language can be used for agents. (Samples in Ada are included.) Agent debug output can be shown. Both text in a log window and symbols on the map can be used to visualize thoughts.
This project is unmaintained and was only relevant for Linux kernel versions before 2.4.
I found a way using GNU Make, pdfinfo (from the poppler package), egrep, sed and bc. The following Makefile will concatenate the files, inserting empty pages where needed so that each subdocument starts on a new paper:
pagecount = $(shell pdfinfo $(1)|egrep "^Pages: *[[:digit:]]+"|sed "s@^Pages: *\([[:digit:]]\+\)@\1@")
odd = $(shell echo $(pagecount)%2|bc|grep 1)
filled = $(1) $(if $(call odd,$(1)),emptypage.pdf)
whole.pdf: 1.pdf 2.pdf 3.pdf 4.pdf 5.pdf 6.pdf 7.pdf 8.pdf 9.pdf
gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=$@ -dBATCH $(foreach x,$^,$(call filled,$x)) || rm -f $@