The UDS (Useful Development Stuff) Collection is a C++ library that provides development and debugging facilities such as automatic searching for memory leaks and zombie objects, backtraces at runtime, an alternative set of function objects, classes for reference counting, copy-on-write and garbage collection, POSIX threads wrapper classes, a socket API that includes support for TCP, UDP, X.25, and Unix domain sockets, m4 macros, and much more.
Universal Embedded SQL Compiler (UESQLC) is a compiler that provides a common way for accessing heterogeneous databases. UESQLC is based on Structured Query Language (SQL) as a standard for accessing data. This interface provides maximum interoperability, i.e. a single application can access different SQL Database Management Systems (DBMS) through a common set of embedded SQL code (UESQL). This enables a developer to build and distribute a client/server application without targeting a specific DBMS.
Ultimate Basketball Challenge is a 5 on 5 basketball game for Unix variants including Linux and FreeBSD. It aims to be fully customizable (add/edit teams, players, stats, courts, arenas, etc.). You can currently play against the basic AI. It is in constant heavy development and new features are added often.
Ultra Monkey is a project to create load balanced and highly available services on a local area network using Open Source components on the Linux operating system. The focus is on producing a scalable, highly available Web farm, though the technology is easily expandable to other services such as email and FTP. It's intended to be a single point of contact for obtaining software and documentation for network engineers. The documentation provided with Ultra Monkey has example topologies and sample configuration files to aid users in designing and constructing a network.
Umix is a program for adjusting sound card volumes and other features in sound card mixers. You can control your volumes, balances, and recording sources flexibly from the command line or with a ncurses user interface with familiar vi/emacs keybindings. Umix supports multiple mixer devices. All settings can be saved and loaded from a file.
Unarc unpacks an archive and creates a top-level directory to unpack into if it's needed. Unarc works with lots of archives, not just tarballs (bz2, zip, and even rpm are supported). There is a companion program arcdir which provides a uniform way to archive directories into tarfiles, zipfiles, etc.
Unifdef is useful for removing #ifdef'ed lines from a file while otherwise leaving the file alone. You specify which symbols are defined or undefined with -D and -U flags, and unifdef removes the corresponding ifdefs, and the enclosed code if appropriate. It's especially useful for removing those "#ifdef BROKEN" and "#ifdef PRIVATE" clauses from code before you release it. Unifdef acts on #if, #ifdef, #ifndef, #elif, #else, and #endif lines, and it knows only enough about C and C++ to know when one of these is inactive because it is inside a comment or a single or double quote.
Unison is a file-synchronization tool for Unix and Windows. It allows two copies of a collection of files and directories to be stored on different hosts (or different disks on the same host), modified separately, and then brought up to date by propagating the changes in each replica to the other. Unison can deal with updates to both replicas of a distributed directory structure. Updates that do not conflict are propagated automatically. Conflicting updates are detected and displayed. Unison can communicate through a direct socket link or through an rsh/ssh tunnel. It uses network bandwidth efficiently.