Software that is specifically made to run on an Ultimate Device. Meaning a 1541Ultimate, Ultimate II+, Ultimate Elite, or a Commodore64 Ultimate.

• ReadyOS - What if a Commodore 64 could feel ready, not just nostalgic? ReadyOS treats waiting as the enemy. It is a keyboard-first, full-screen terminal-style environment built around instant app switching, suspend/resume, shared clipboard and history, and deeper links between apps.
• Command64 OS - MS-DOS style operating system for the C64 with a REU size of 1MB minimum

• geoIRC - IRC client for GEOS/GDOS64. Connect to any IRC channel available on the internet. Only works via Ethernet!
• GeoUTools - Tools for use with Ultimate devices without having to leave the GUI, or even having to open the Ultimate menu! Also works in 80-column mode in GEOS128 with Ultimate cartridge.

• SID-Wizard 1.97 - SID tracker for Commodore 64/128 as well as for Windows, MacOS, and Linux. Create music for up to 4 SID chips (real, or virtual). Includes a large instrument library, example tracks, MIDI, and a piano roll view.

• C64UHEX - C64UHEX is a native hex editor for the Commodore 64. It provides professional, byte-level inspection and modification of binary data using a true PETSCII interface, respecting the constraints and character semantics of the original platform.
• AdvEditC64 - Advanced Commodore Editor - Advanced Commodore Editor is a native, full-screen text editor designed specifically for the Commodore 64, with special attention given to the C64 Ultimate and its SD/USB-based storage workflow. The editor is inspired by the philosophy of the Linux nano editor: Simple controls, fast interaction, minimal cognitive overhead, and clear on-screen prompts while respecting the technical constraints and historical behavior of vintage hardware.

Games specifically created to make use of the features of an Ultimate device.

• No known games at the time of this writing

• Infinite Matter
• Ultiverzum
• The Tuneful Eight (included on The Very Second)
• UltimateDemo2026
• Raster Split Fun

• 

  

  Ultimate Opus

  Ultimate Opus - A dual-pane file manager for Ultimate devices, released by Lft. Current version is 0.2, released in 2014. No active development.

• UBoot64-v2 - Boot manager/Boot menu for Ultimate devices.

Software that is specifically made to run on a computer other than the C64 or C128. The software below is designed for use WITH but not ON an Ultimate device.

• ALBERT - Win/Mac/Linux application to create C64 graphics, it can send its images to your Ultimate device, save them as .PRG and other formats. ALBERT allows its users to create Commodore 64 images that extend into the left and right borders of the visible screen, with sprites to display the extra pixels, using an uncomplicated drawing workflow, without requiring the assistance of a coder.

Tools to prepare data on an other computer before moving it over to the C64U to be used there.

• GameBase64 Game Organizer - A Python utility to organize Commodore 64 games from zip archives into a structured folder hierarchy based on metadata from VERSION.NFO files.