Comparison

RETRO FORTH vs My Lisp

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

RETRO FORTH

A compact and adaptable concatenative programming language designed for ease of learning and customization. It features a code editor, interactive listener, and support for Gopher servers, allowing for flexible development.

Highlights
  • Concatenative programming language
  • Code editor with Markdown subset
  • Literate programming style
  • Interactive listener interface
  • Gopher server data fetching
  • File manager
  • Documentation browser
Features
Read full description

RETRO FORTH is a concatenative programming language with roots in Forth. Designed to be compact, learnable, and easy to adapt to specific needs, it has been developed and refined through continual use by a small community over more than a decade. Forth is a stack based programming language created in the late 1960's by Chuck Moore. Over the intervening decades it has evolved through use, with many dialects along the way. The Retro dialect was created in the late 1990's, and has been continually developed and supported for over 15 years. It is a structured, imperative stack-based language with modern facilities including quotations and reflection. It features: - latest version of the RETRO language - a code editor using Markdown subset - literate programming style - code is extracted from fenced blocks in Markdown source allowing easy mixing of code and commentary - allows use of unicode & emoji in source & commentary - interactive listener interface for quick interactions - simple console output and text input - editor provides quick access to numbers and symbols - support for fetching textual data from Gopher servers - file manager - documentation browser It also includes documentation and several optional examples.

About

My Lisp

A comprehensive Lisp programming environment for iOS and macOS devices. It offers a local interpreter, editor, and extensive libraries for learning and developing Lisp programs, including advanced mathematical functions and symbolic derivation.

Highlights
  • Local Lisp interpreter
  • Integrated editor
  • Core and mathematical operators
  • Advanced mathematics functions
  • Symbolic derivation module
  • Library and example files
  • User and reference manuals
Features
Read full description

My Lisp is a complete and universal Lisp environment running directly on the iPhone, iPad, and Mac. This interpreter is true to the original John McCarthy Lisp implementation with the fundamental 7 operators quote, atom, eq, car, cdr, cons, cond, along with lambda and label. My Lisp also contains core and mathematical operators borrowed from other Lisp dialects (Le Lisp, Lisp 1.5, MacLisp, Common Lisp and Scheme to name a few) to make it easy to learn, program, and most importantly, enjoy Lisp. It also features built-in functions for advanced mathematics, including complex numbers and numerical analysis (roots and zeros finder, integral approximation). The complete description of the fundamental, core, and built-in functions is available using a set of library functions completely written in My Lisp. My Lisp offers an interpreter and an editor, all working on the iPhone, iPad, and Mac, and most importantly, without requiring any server connection, that is, the interpreter is executing locally on the iPhone, iPad or Mac My Lisp is installed on. Library and example files contain the source code of classical functions and problems solved by My Lisp and may be used as reference to learn Lisp and develop other programs. They include classical puzzles (hanoi and n-queens), basic mathematical functions (gcd, lcm, factorial, fibonacci, prime?), and the historical apply, mapcar and maplist functions. The Lambda Calculus example file contains various functions related to Lambda Calculus and Combinators, with alpha-conversion, beta-reduction, de Bruijn notations, etc. As a special note, the example file Symbolic Derivation contains a complete yet extensible symbolic derivation module allowing to compute the formal derivation of virtually any symbolic function expressed as a Lisp expression. A user manual and a reference manual are available from within the application but also on My Lisp web site (https://lisp.lsrodier.net) and in Apple Books. The complete source code of the library and example files is part of My Lisp. Last but not least, this overview couldn’t end without a sample definition of the notorious REPL function: (define (REPL eval_me) (REPL (println (eval (read)))))

Screenshots

RETRO FORTH4 screens
My Lisp4 screens

Verdict

The call

The clearest difference is price: RETRO FORTH at Free against My Lisp's $3.99. RETRO FORTH also leads on rating (4.4 vs 4.1) and iOS requirement (12.4 vs 18.0). My Lisp's advantage is review sentiment (69% vs 33%) and chart position (#81 vs unranked). On update cadence, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

RETRO FORTH is free to download; My Lisp costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

RETRO FORTH holds the better App Store score, 4.4 against 4.1. Both are backed by a comparable volume of ratings — 5 and 17 respectively. Written reviews complicate that: 33% of RETRO FORTH's written reviews are positive against 69% of My Lisp's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

RETRO FORTH ships an update monthly, My Lisp every 6 weeks. The most recent releases landed on October 16, 2026 and October 12, 2026 respectively.

Scorecard7 real differences · 4 level
RETRO FORTH versus My Lisp: the parameters behind the verdict, then further details
ParameterRETRO FORTHMy Lisp
PriceFree — better$3.99
Rating4.4 (5 ratings) — better4.1 (17 ratings)
Positive reviews33.3% of reviews68.8% of reviews — better
Number of ratings517 — better
Update frequencyMonthly — betterEvery 6 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
Best chart rank—#81 — better
DevicesiPhone, iPad, iPodiPhone, iPad, Mac
Requires iOS12.4 — better18.0
Further details — not scored
Size4 MB19 MB
Age rating4+4+
DeveloperCharles ChildersLaurent Rodier

Customer experience

RETRO FORTH

All ratings5 ratings
Positive80.0%
Neutral20.0%
Negative0.0%
Written reviews3 reviews
Positive33.3%
Neutral66.7%
Negative0.0%

My Lisp

All ratings17 ratings
Positive82.4%
Neutral0.0%
Negative17.6%
Written reviews16 reviews
Positive68.8%
Neutral12.5%
Negative18.8%

In-app purchases

None

RETRO FORTH

No in-app purchases

None

My Lisp

No in-app purchases

Questions

Is RETRO FORTH free?
RETRO FORTH is free to download, with no in-app purchases.
Is My Lisp free?
My Lisp costs $3.99, with no in-app purchases.
Which has better reviews, RETRO FORTH or My Lisp?
RETRO FORTH is rated higher. RETRO FORTH averages 4.4 out of 5 from 5 ratings, while My Lisp averages 4.1 from 17 ratings.
Do RETRO FORTH or My Lisp have ads?
Neither RETRO FORTH nor My Lisp shows ads.
Which is updated more often, RETRO FORTH or My Lisp?
RETRO FORTH ships an update monthly, and My Lisp every 6 weeks. Most recently, RETRO FORTH was updated on October 16, 2026 and My Lisp on October 12, 2026.

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