In the places I go, there are things that I see

That I never could spell if I stopped with the Z.

I'm telling you this ’cause you're one of my friends.

My alphabet starts where your alphabet ends.

                                                                -- Doctor Seuss

Software Available for Download

Follow the underlined links.

    Macintosh™ Shareware*:

        Wraith Scheme (64-bit application)

            Wraith Scheme implements the R5 version of the Scheme programming language.

            This version runs on Macintoshes with Intel processors that can run 64-bit

            applications, that use Mac OS 10.6 (“Snow Leopard”) or a later Mac OS.  The

            64-bit version of Wraith Scheme is newer and has more features than the 32-bit

            version; get this one, not the 32-bit version, if your Macintosh can run it.

        Wraith Scheme (32-bit application)

            Wraith Scheme implements the R5 version of the Scheme programming language.

            The 32-bit version is universal binary. I keep it available for users who have older

            Macintoshes; the 64-bit version is newer, better maintained, and has more features.

        Pixie Scheme II (64-bit application)

            Pixie Scheme II implements the R5 version of the Scheme programming language.

            It runs on Macintoshes with Intel processors that can run 64-bit applications, that

            use Mac OS 10.6 (“Snow Leopard”) or a later Mac OS. Pixie Scheme II was a

            design and development prototype for Pixie Scheme III; it has fewer features and

            a simpler user interface than Wraith Scheme.

        Percival

            “Percival” is a simple pixel-oriented image editor intended for customization and

            touch-up of icons or similar small images. Percival is universal binary.

        Pixie Scheme

            Pixie Scheme -- this original version, not Pixie Scheme II or Pixie Scheme III --

            was released January, 1991. No typo, I really mean 1991. It only runs on very old

            Macintoshes. I have re-released it for the folks who collect old Macintoshes.


    Raspberry Pi 400 Shareware*

        Weasel Scheme

            Weasel Scheme implements the R5 version of the Scheme programming language.

            This version runs on Raspberry Pi 400s using Debian/GNU Linux 11 (bullseye).


    Macintosh Freeware:

        Red Sky

            Red Sky is a specialized screen-reddening utility for amateur astronomers who use

            an Apple Macintosh outside, at night. Red Sky is universal binary.


     iPad™, iPhone™ and iPod Touch™ Apps:

        Pixie Scheme III

            Pixie Scheme III implements the R5 version of the Scheme programming language.

            It runs on the iPad and is for sale in the App Store.

        1…

            1… provides an array of clickable counters, as a productivity aid for counting things.

            It runs on the iPad and is for sale in the App Store.

        Features of Light and Darkness

            Features of Light and Darkness demonstrates features of human color vision

            with light sources of different kinds (different spectra) and different brightnesses.

            It runs on the iPad, iPhone, and iPod Touch, and is for sale in the App Store.


    Source Code:

        Source code for the 64-bit version of Wraith Scheme, for Pixie Scheme II, and for

        Pixie Scheme III is available under the GNU General Public License.


    Talks and Slides:

        I have given a number of talks on various aspects of my Scheme systems, and on

        related topics:  Here are links to some of them:

            Building Wraith Scheme From Scratch (PDF -- 3 June 2011).

            Parallel Scheme on the Cloud: First Steps (PDF -- 16 November 2010).

            Randomized Parallel Marking in Mark-and-Copy Garbage Collectors

                (PDF -- 9 May 2012).

            Thoughts On Massively Parallel Computing (PDF -- 3 May 2010).


   * “Shareware” can mean many things: To me, it means public service. These shareware applications are fully functional as downloaded -- no activation codes, nothing to buy, and no pop-up reminders about shareware donations. (Donations are welcome, if you want to make one.)  Any lack of functionality is likely my fault: Send in a bug report so I can get busy fixing it. (Note that there are occasional “platform-dependent” bugs, which I may not be able to detect, simply because I do not have the right combination of hardware and software to elicit them. So please report bugs!)


    If you need assistance with any of this software, or if you have a complaint, an enhancement request, or a bug report, or even if you are simply curious about how something works, by all means let me hear from you. My EMail address is Jay_Reynolds_Freeman@mac.com.