This app lets you draw diagrams, tables, tree view, art and more using only characters.
There are many stiles to choose from and multiple tools available to use such as:
      
        Rectangle
        Filled Rectangle
        Cartesian, freehand and stepped line
        Freehand Brush
        Text with FIGlet fonts
        Table
        Tree View
        Eraser
        Character Picker
        Select and move
      
    

ASCII Draw


            YOGA Image Optimizer is a free tool to convert and optimize images. It currently
            supports JPEG, PNG and WebP as output formats and much more image formats
            are supported as input.
        
      
            With YOGA, you will be able to save about 30 % of space on JPEGs and 20 % on PNGs.
            On WebP images, you will only save few percents... but converting a
            JPEG to a lossy WebP can reduce image size to a half and converting
            a PNG to a lossy WebP can save you 35 % on average.
        
      
            Please note that image optimization can be slow and may require a lot of RAM, especially
            for JPEGs. For example, the JPEG encoder needs 300 MB of RAM and 3 min
            per Mpix (PNG and WebP encoders are less resource hungry).
        
    

YOGA Image Optimizer

Convert and optimize JPEG, PNG and WebP images


      Weasis is a multipurpose standalone and web-based DICOM viewer with a highly modular architecture. It is a very popular clinical viewer used in healthcare by hospitals, health networks, multicenter research trials, and patients.
    
      
        Flexible integration to PACS, VNA, RIS, HIS or PHR
        Responsive user interface and work well on high DPI screens
        Web access through weasis protocol
        Multi-language support
        Configuration of preferences on server-side and client-side
        API for building custom plug-ins
        DICOM Send (storeSCU and STOW-RS)
        DICOM Query/Retrieve (C-GET, C-MOVE and WADO-URI) and DICOMWeb (QUERY and RETRIEVE)
        Dicomizer module (allow importing standard images and convert them in DICOM)
      
    

Weasis

PhotoCollage allows you to create photo collage posters. It assembles the input photographs it is given to generate a big poster. Photos are automatically arranged to fill the whole poster, then you can change the final layout, dimensions, border or swap photos in the generated grid. Eventually the final poster image can be saved in any size.The algorithm generates random layouts that place photos while taking advantage of all free space. It tries to fill all space while keeping each photo as large as possible.PhotoCollage does more or less the same as many commercial websites do, but for free and with open-source code.

PhotoCollage

Graphical tool to make photo collage posters

Aegisub is a free, cross-platform open source tool for creating and modifying subtitles. Aegisub makes it quick and easy to time subtitles to audio, and features many powerful tools for styling them, including a built-in real-time video preview.
      Aegisub was originally created as a tool to make typesetting, particularly in anime fansubs, a less painful experience. At the time of the start of the project, many other programs that supported the Advanced Substation Alpha format lacked (and in many cases, still lack; development on several competing programs have since been dropped for various reasons completely unrelated to Aegisub) many vital functions, or were too buggy and/or unreliable to be really useful.
      Since then, Aegisub has grown into a fully fledged, highly customizable subtitle editor. It features a lot of convenient tools to help you with timing, typesetting, editing and translating subtitles, as well as a powerful scripting environment called Automation (originally mostly intended for creating karaoke effects, Automation can now be used much else, including creating macros and various other convenient tools).
      Some highlights of Aegisub:
      
        Simple and intuitive yet powerful interface for editing subtitles
        Support for many formats and character sets
        Powerful video mode
        Visual typesetting tools
        Intuitive and customizable audio timing mode
        Fully scriptable through the Automation module
      
    

Aegisub

Mandelbulber2 creatively generates three-dimensional fractals. Explore trigonometric, hyper-complex, Mandelbox, IFS, and many other 3D fractals. Render with a great palette of customizable materials to create stunning images and videos.Features:

Mandelbulber2

Free and open source 3D fractals generator

DIY Layout Creator (DIYLC in short) is a powerful, but simple to use and intuitive tool for visualizing electronic circuit schematic and layout diagrams. It provides a simple WYSIWYG interface and supports designing PCB, vero-board, point-to-point, perf-board and guitar wiring diagrams as well as circuit schematics quickly and without the steep learning curve.In addition to drawing, the projects can be shared with other users through the integrated 'Cloud' feature. Guitar wiring diagrams can be analyzed and debugged.DIYLC is geared towards DIY hobby enthusiasts and is developed by an enthusiast with the help of the large community of DIY builders.

DIY Layout Creator

Circuit layout design tool supporting PCB, vero-board, point-to-point, perf-board and guitar wiring diagrams

Kindle Comic Converter is an app that allows you to transform your PNG, JPG, GIF, CBZ, CBR
    and CB7 files into EPUB or MOBI format e-books. Preparing comics and manga for your E-Ink
    device was never easier.
      KCC was initially developed for Kindle but currently it outputs valid EPUB 3.0 and CBZ
    so despite its name, KCC is tool that every E-Reader owner can happily use.
    Additionally KCC will process your images and make sure that your comics and manga
    are fully optimized for E-Ink displays.
      NOTE: Please put kindlegen_linux_i386 to ~/.var/app/io.github.ciromattia.kcc/data/kindlegen
    

Kindle Comic Converter

An app that allows you to transform your PNG, JPG, GIF, CBZ, CBR and CB7 files into EPUB or MOBI format e-books

Penpot is the first Open Source design and prototyping platform meant for cross-domain teams. Non dependent on operating systems, Penpot is web based and works with open web standards (SVG). For everyone and empowered by the community.

This is not an official app by Penpot.

Penpot Desktop

Pencil2D is a 2D animation program that lets you easily create hand-drawn graphics using both bitmap and vector graphics.

Pencil2D

2D animation software supporting bitmap and vector graphics

XnSketch allows you to turn your photos into cartoon or sketch images.
      Features:
      
        18 different effects (black strokes, white strokes, pastel, pencil sketch, colored sketch, ...)
        Edge strength, and opacity adjustement
        Contrast, brightness, saturation adjustement
        Save or share the result
      
      XnSketch is provided as freeware.
      You are granted the right to use and to make an unlimited number of copies of this software.
      Copyright (C) 1997-2016 Pierre-e Gougelet. All rights reserved.
    

XnSketch

LightZone is a professional-level digital darkroom and photo editor for Mac, Windows, and Linux. It includes RAW processing and editing. Rather than using layers in the way that other photo editors do, LightZone lets the user build up a stack of tools which can be rearranged, readjusted, turned off and on, and removed from the stack. It's a completely non-destructive editor, where any of the tools can be re-adjusted or modified later — even in a different editing session. A tool stack can even be copied to a batch of photos at one time. LightZone always operates in a 16-bit linear color space with the wide gamut of ProPhoto RGB.

LightZone

SolveSpace is a free (GPLv3) parametric 3d CAD tool. Applications include:Modeling 3d parts — draw with extrudes, revolves/helix, and Boolean operationsModeling 2d parts — draw the part as a single section, and export; use 3d assembly to verify fitModeling 3d-printed parts — export the STL or other triangle mesh expected by most slicersPreparing 2D CAM data — export 2d vector art for a waterjet machine or laser cutterMechanism design — use the constraint solver to simulate planar or spatial linkagesPlane and solid geometry — replace hand-solved trigonometry with a live dimensioned drawing

SolveSpace

Pix is an image gallery and image viewer. Pix can be used to open images with other applications like an image editor, add tags to the files, add annotations to pictures, rotate and share them.
    

Aliza MS is a standalone medical DICOM viewer
      
        2D and 3D views with many tools
        3D view also for non-uniform images
        Consistently de-identify DICOM, maintain integrity
        DICOM Study multi-view with intersection lines and side-by-side view
        Volume Rendering, multi-planar reconstruction (MPR)
        2D+t and 3D+t animations
        DICOM metadata viewer, DICOM 2024b dictionary
        Fast directory scanner, DICOMDIR
        RTSTRUCT contours
        Proper measurement in Ultrasound Calibrated Regions
        Encapsulated transfer syntaxes incl. J2K and HTJ2K
        Most IODs are supported incl. Structured Reports, Key Objects Selection, Grayscale Softcopy Presentation State
      
    

Aliza MS


            A VTK-based 3D viewer following the KISS principle, so it is minimalist,
            efficient, has no GUI, has simple interaction mechanisms and is fully
            controllable using arguments on the command line.
        
    

Synfig Studio is a free and open-source 2D animation software, designed as powerful industrial-strength solution for creating film-quality animation using a vector and bitmap artwork. It eliminates the need to create animation frame-by frame, allowing you to produce 2D animation of a higher quality with fewer people and resources.Features:Can manipulate vector and bitmap artworkAutomatic tweening (independent from FPS)Multitude of layers of various types (geometry primitives, shapes, gradients, fratals)Full-featured bone systemFilters and effects for compositing (blurs, distortions, color manipulation, masks)All color operations use High Dynamic-Range Imaging (HDRI)Pentablet-friendly toolsSound supportLinking data on file- or parameter-levelAutomatic animation using mathematical functions

Synfig Studio

Create and edit 2D animations and compositions


      Bforartists is a complete, free and opensource 3D suite to create CG content. It offers you the full 3D art pipeline to create game graphics, pre-rendered movies and stills. From modeling, sculpting, texturing, rigging, animation, rendering, up to post processing. 

      Bforartists gives the full power of Blender but with a nicer UI and user experience. Keyboard-only features are now available through the UI, nodes are given proper descriptions, icons are colored to make things easier to find. Everything is tailored for the user experience.
    
    

Bforartists


        KColorChooser is a color palette tool, used to mix colors and create custom
        color palettes.  Using the dropper, it can obtain the color of any pixel on
        the screen. A number of common color palettes are included, such as the standard Web colors
        and the Oxygen color scheme.
    
    

KColorChooser


      Gromit-MPX is an on-screen annotation tool that works with any Unix desktop environment under X11 as well as Wayland.
    
      
      Its main use is for making presentations of some application. Normally, you would have to move the mouse pointer around the point of interest until hopefully everybody noticed it. With Gromit-MPX, you can draw everywhere onto the screen, highlighting some button or area.
    
      Key features include:
      
        Desktop-independent. Gromit-MPX works with GNOME, KDE, XFCE, ... under X11 as well as with a Wayland session
        Hotkey-based. Does not get into your way of doing things by sticking some UI widget on your desktop
        Configurable. You are free to change key bindings as well as drawing tool configuration
        Multi-Pointer. Under X11, it enables graphical annotations with several pointers at once
        Fast. Where available, Gromit-MPX makes use of Compositing
      
    

Gromit-MPX

Gromit-MPX is a tool to make annotations on the screen

CorePaint is a simple bitmap painting software to produce very simple graphics.

CorePaint

A simple tool for cropping and downsizing images. Suitable for avatars or cropping photos for use as desktop wallpapers. Convert PNG to JPG. Export in one click to your Pictures folder.

Avvie

Compress your images with ease without the cost of loosing the images quality using JpegOptim and OptiPng.Features:Compress bmp, jpg / jpeg, png, pnm and tiff with lossless compressionWorks offline, always ready where and whenever neededA clean interface, optimize your images effortlesslyEasily quit the application by pressing Ctrl + Q

Image Optimizer


      FontForge is a font editor for outline and bitmap fonts that lets you create,
      edit, or convert, a range of fonts, including PostScript, TrueType, OpenType,
      cid-keyed, multi-master, cff, SVG and BitMap (bdf, FON, NFNT) fonts.
    
      
      FontForge is free Open Source Software written to run on various computer operating
      systems. You can use FontForge Graphically or as a command-line tool.
    
      
      Learning to use FontForge is easy, and there are various tutorials available beginning
      with the basics up to more advanced features such as making and using scripts.
    
    

FontForge

Luminance HDR is an application for taking a set of pictures of the same scene with different exposure settings and creating a high dynamic range (HDR) image. It supports a range on input image formats, including JPEG, TIFF and RAW. It provides eleven tone mapping operators for converting the HDR back to a low dynamic range image (LDR). It can also rotate, crop, resize HDR images and apply projective transformations. HDR images can be created and tone mapped in batch and a tool is provided for copying EXIF data from/to a set of images.

Luminance HDR

Entangle is a program used to control digital cameras that are connected to the computer via USB.Entangle can trigger the camera shutter to capture new images. When supported by the camera, a continuously updating preview of the scene can be displayed prior to capture. Images will be downloaded and displayed as they are captured by the camera. Entangle also allows the settings of the camera to be changed from the computer.Entangle is compatible with most DSLR cameras from Nikon and Canon, some of their compact camera models, and a variety of cameras from other manufacturers.

Entangle

Glaxnimate is an open-source vector animation and motion design desktop application.Features:TweeningPrecompositionsTime StretchingMotion Along PathShape ModifiersText SupportAnimated GradientsRaster to VectorScripting SupportSupported file formats:LottieAnimated SVGAnimated WebPAnimated Vector DrawablesRIVEVideo ExportSpritesheet Export

Glaxnimate

QElectroTech is a Qt5 application to design electric diagrams. It uses XML files for elements and diagrams, and includes both a diagram editor, an element editor, and a titleblock editor.

QElectroTech

HotShots is an application for capturing screens and saving them in a variety of image formats as well as adding annotations and graphical data (arrows, lines, texts, ...)

HotShots

Powerful and simple to use screenshot software

Pick lets you pick colours from anywhere on your screen. Choose the colour you want and Pick remembers it, names it, and shows you a screenshot so you can remember where you got it from.Zoom all the way in to pixels to pick just the right one. Show your colours in your choice of format: rgba() or hex, CSS or Gdk or Qt or Android, whichever you prefer. Copy to the clipboard ready for pasting into code or graphics apps.

Gráficos e Fotografia