Scheme 48 is an implementation of Scheme based on a byte-code interpreter and is designed to be used as a testbed for experiments in implementation techniques and as an expository tool.

Unsyntax is an implementation of the Scheme programming language, specifically of its R7RS standard, and includes a number of extensions. Unsyntax evaluates Scheme expressions and compiles and runs Scheme programs by first expanding them into a minimal dialect of R7RS (small) without any syntactic extensions. The resulting expression or program is then evaluated by an existing Scheme implementation.

Gauche is a R7RS Scheme scripting engine aiming at being a handy tool that helps programmers and system administrators to write small to large scripts quickly. Quick startup, built-in system interface, native multilingual support are some of the goals. Gauche comes with a package manager/installer gauche-package which can download, compile, install and list gauche extension packages.

GNU/MIT Scheme is an implementation of the Scheme programming language. It provides an interpreter, a compiler and a debugger. It also features an integrated Emacs-like editor and a large runtime library.

GNU SCM is an implementation of Scheme. This implementation includes Hobbit, a Scheme-to-C compiler, which can generate C files whose binaries can be dynamically or statically linked with a SCM executable.

Scheme 9 from Empty Space (S9fES) is a mature, portable, and comprehensible public-domain interpreter for R4RS Scheme offering:

• bignum arithmetics

• decimal-based real number arithmetics

• support for low-level Unix programming

• cursor addressing with Curses

• basic networking procedures

• an integrated online help system

• loads of useful library functions

Gerbil is an opinionated dialect of Scheme designed for Systems Programming, with a state of the art macro and module system on top of the Gambit runtime. The macro system is based on quote-syntax, and provides the full meta-syntactic tower with a native implementation of syntax-case. It also provides a full-blown module system, similar to PLT Scheme's (sorry, Racket) modules. The main difference from Racket is that Gerbil modules are single instantiation, supporting high performance ahead of time compilation and compiled macros.

Gambit consists of two main programs: gsi, the Gambit Scheme interpreter, and gsc, the Gambit Scheme compiler. The interpreter contains the complete execution and debugging environment. The compiler is the interpreter extended with the capability of generating executable files. The compiler can produce standalone executables or compiled modules which can be loaded at run time. Interpreted code and compiled code can be freely mixed.

TinyScheme is a light-weight Scheme interpreter that implements as large a subset of R5RS as was possible without getting very large and complicated.

It's meant to be used as an embedded scripting interpreter for other programs. As such, it does not offer an Integrated Development Environment (IDE) or extensive toolkits, although it does sport a small (and optional) top-level loop.

As an embedded interpreter, it allows multiple interpreter states to coexist in the same program, without any interference between them. Foreign functions in C can be added and values can be defined in the Scheme environment. Being quite a small program, it is easy to comprehend, get to grips with, and use.

Pre-Scheme is a statically compilable dialect of Scheme, used to implement the Scheme 48 virtual machine. Scheme 48 ships with a Pre-Scheme to C compiler written in Scheme, and a runtime library which allows Pre-Scheme code to run as Scheme.

femtolisp is a scheme-like lisp implementation with a simple, elegant Scheme dialect. It is a lisp-1 with lexical scope. The core is 12 builtin special forms and 33 builtin functions.

TR7 is a lightweight Scheme interpreter that implements the revision R7RS small of scheme programming language.

It is meant to be used as an embedded scripting interpreter for other programs. A lot of functionality in TR7 is included conditionally, to allow developers freedom in balancing features and footprint.

dtach is a tiny program that emulates the detach feature of screen, allowing you to run a program in an environment that is protected from the controlling terminal and attach to it later.

reptyr is a utility for taking an existing running program and attaching it to a new terminal. Started a long-running process over ssh, but have to leave and don't want to interrupt it? Just start a screen, use reptyr to grab it, and then kill the ssh session and head on home.

GNU Screen is a terminal window manager that multiplexes a single terminal between several processes. The virtual terminals each provide features such as a scroll-back buffer and a copy-and-paste mechanism. Screen then manages the different virtual terminals, allowing you to easily switch between them, to detach them from the current session, or even splitting the view to show two terminals at once.

Byobu is a Japanese term for decorative, multi-panel screens that serve as folding room dividers. The Byobu software includes an enhanced profile, configuration utilities, and system status notifications for the GNU Screen window manager as well as the Tmux terminal multiplexer.

abduco provides session management i.e. it allows programs to be run independently from their controlling terminal. That is, programs can be detached---run in the background---and then later reattached.

Scribus is a desktop publishing (DTP) application and can be used for many tasks; from brochure design to newspapers, magazines, newsletters and posters to technical documentation. Scribus supports professional DTP features, such as CMYK color and a color management system to soft proof images for high quality color printing, flexible PDF creation options, Encapsulated PostScript import/export and creation of four color separations, import of EPS/PS and SVG as native vector graphics, Unicode text including right to left scripts such as Arabic and Hebrew via FreeType.

sg3-utils is a collection of utilities for devices that use the Small Computer System Interface (SCSI) command set. It includes utilities to read data from, write data to, control, modify, and query the state of SCSI devices.

For example, this package provides command-line tools to:

• copy data based on dd syntax and semantics (called sg_dd, sgp_dd, and sgm_dd)

• check INQUIRY data and VPD pages (sg_inq)

• check mode and log pages (sginfo, sg_modes, and sg_logs)

• spin up and down disks (sg_start)

• do self-tests (sg_senddiag)

• parse sense data (sg_decode_sense)

• and perform various other functions.

In addition, this package includes a library, called libsgutils, which can be used in C and C++ programs to interact with SCSI devices.

Libiscsi is a client-side library to implement the iSCSI protocol that can be used to access the resources of an iSCSI target. It is fully asynchronous with regards to iSCSI commands and SCSI tasks, but a synchronous layer is also provided for ease of use for simpler applications.

lsscsi lists SCSI logical units or SCSI targets. It can also list NVMe namespaces or controllers and show the relationship between a device's primary node name, its SCSI generic (sg) node name and its kernel name.

SDL_image is an image file loading library for SDL that supports the following formats: BMP, GIF, JPEG, LBM, PCX, PNG, PNM, TGA, TIFF, WEBP, XCF, XPM, and XV.

SDL_mixer is a multi-channel audio mixer library for SDL. It supports any number of simultaneously playing channels of 16 bit stereo audio, plus a single channel of music. Supported formats include FLAC, MOD, MIDI, Ogg Vorbis, and MP3.

This package supports two MIDI backends, selectable at runtime. To use the newer fluidsynth library, install a soundfont such as fluid-3 and specify it using the SDL_SOUNDFONTS environment variable. For the legacy timidity backend, install a patch set such as freepats and set the path to the configuration file with TIMIDITY_CFG.

This package provides Graphics drawing primitives and other support functions wrapped up in an add-on, C-based library for the Simple Direct Media (SDL) cross-platform API layer.