Hot Soup Processor

Hot Soup Processor (HSP) is a free, BASIC-inspired scripting language from Japan, designed to make it easy for beginners and hobbyists to build Windows games, tools, and graphical applications without the friction of a traditional compile-link-run cycle. Created by the developer known as Onitama under the onion software name, HSP pairs an approachable, command-oriented syntax with built-in support for 2D graphics, input handling, and sound — the ingredients needed to make something visible and interactive almost immediately. Though it has always been most popular in Japan, HSP has quietly endured for roughly three decades, evolving from a small Windows utility into an open-source, cross-platform scripting system while keeping its beginner-first spirit intact.

History & Origins

A Tool for Quick Windows Programs

Development of Hot Soup Processor began around 1994, in the era when Microsoft Windows was becoming the dominant consumer platform but writing native Windows applications in C with the Win32 API was famously tedious. Onitama’s goal was pragmatic: a scripting tool that let an ordinary user open an editor, type a few lines, and immediately see a window, a sprite, or a sound — without wrestling with compilers, linkers, or boilerplate.

The first public release, HSP1, appeared in 1996 as freeware. It leaned heavily on 2D graphics primitives and an interpreted execution model, so scripts ran directly rather than being compiled to native code first. (Onion software’s own copyright notices date the project from 1997, which is why that year is sometimes cited; the first publicly distributed version is generally placed in 1996.)

From Freeware Utility to Maturing Language

Through the late 1990s and early 2000s, HSP grew from a graphics toy into a more capable scripting environment. The HSP2 series added module and plug-in mechanisms (such as standard module sets) that let the community extend the language, and HSP’s free availability made it a natural fit for the burgeoning Japanese doujin (self-published) software and game scene.

The most significant turning point came in 2004 with HSP version 3.0 (HSP3) — a comprehensive rewrite of the language and its runtime. HSP3 modernized the syntax, reworked the compiler and intermediate execution model, and introduced a more structured approach to variables and program organization while preserving the gentle learning curve that defined the language.

Going Open Source: OpenHSP

In 2009, the toolchain was released as open source under a modified BSD license through the OpenHSP project. This was a meaningful shift: the compiler (hspcmp), the command-line runtime (hsp3cl), the editor (hsed), and the various runtimes became available for inspection, contribution, and — crucially — porting to platforms beyond Windows. OpenHSP is maintained by onion software with community involvement, with the source hosted publicly on GitHub.

Design Philosophy

HSP’s design choices all point in one direction: lower the barrier between “I have an idea” and “it runs on screen.”

Immediacy Over Ceremony

HSP descends from BASIC, and it inherits BASIC’s emphasis on directness. There is minimal setup, no mandatory project scaffolding, and historically no separate compile step the user has to think about — you write a script and run it. For a newcomer, the gap between writing a line and seeing its effect is small, which is exactly what keeps beginners engaged.

Graphics and Interactivity Built In

Where many general-purpose languages treat graphics, windowing, and sound as external libraries to be located and configured, HSP bakes these capabilities into the language itself. Drawing to a window, loading an image, playing a sound, or reading the keyboard and mouse are first-class operations. This makes HSP feel less like a general scripting language and more like a small, integrated environment for building interactive programs.

Free and Self-Contained

HSP has been free from its earliest releases, and it can produce standalone Windows executables that run without a separate interpreter install. That combination — no cost, no deployment friction — is a large part of why it spread through hobbyist and student communities.

Key Features

Command-Oriented, BASIC-Style Syntax

HSP scripts read as sequences of commands and assignments, in the BASIC tradition. The style is forgiving and readable for beginners, favoring named commands over dense symbolic syntax.

Built-In 2D Graphics and Media

Core language facilities cover screen drawing, image loading and blitting, text rendering, sound playback, and input — the standard toolkit for 2D games and graphical utilities.

Standalone Executables

HSP can package a script into a self-contained Windows executable, allowing developers to distribute finished tools and games to users who do not have HSP installed.

Extensibility via Plug-ins and Modules

The language supports modules and plug-ins, letting the community add functionality (additional graphics backends, helpers, and bindings) without modifying the core. This extensibility was central to HSP2’s ecosystem and continues in HSP3.

Modernization in the HSP3 Era

Across the 3.x line, HSP gained more structured language features — including typed variables and property-style access — alongside infrastructure improvements such as 64-bit compatibility and native UTF-8 handling, modernizing the language for contemporary systems while keeping older scripts in mind.

HSP3Dish: A Portable Runtime

HSP3Dish, introduced around 2010 (in the 3.3 generation), is a streamlined runtime built on OpenGL ES and HTML5. It lets a subset of HSP run on mobile (iOS, Android), Linux, and the web (WebGL), making HSP one of the few BASIC-lineage hobbyist languages with a path to modern mobile and browser targets.

Evolution

HSP’s trajectory can be read in three broad phases:

The 3.x line has been remarkably long-lived: HSP 3.51 (2019), 3.6 (2021), and 3.7 (2025) represent steady, incremental maintenance rather than disruptive reinvention — a pattern consistent with a mature tool serving a stable, dedicated community.

Platform Support

HSP began as, and remains primarily, a Windows tool — that is where it is most fully featured and where its executable-export workflow originated. Through the OpenHSP project, the toolchain officially supports Linux (with an X Window System GUI environment) and Raspberry Pi (Raspbian / Raspberry Pi OS) according to the project’s documentation.

Beyond the desktop, the HSP3Dish runtime extends a portable subset of HSP to mobile (iOS, Android) and the web (HTML5 / WebGL). Historically, ports for older platforms such as classic Mac OS have also been noted, though Windows has always been the primary, best-supported target. Because support and platform availability vary by version and by runtime (full HSP vs. HSP3Dish), developers targeting non-Windows platforms should consult the current OpenHSP documentation for the specifics that apply to their version.

Current Relevance

As of 2026, HSP remains actively maintained by onion software, with the HSP 3.7 line as the current stable release and copyright notices spanning 1997–2025. Its community continues to be centered in Japan, where the long-running HSP Programming Contest and an established base of documentation, tutorials, and shared scripts keep the language alive for hobbyists, students, and indie developers.

HSP is unmistakably a niche language by global standards — it never sought mainstream international adoption, and its documentation and community are predominantly Japanese. But within that niche it is durable and genuinely useful: a free, low-friction way to make small graphical programs, with an open-source toolchain and a surprising amount of cross-platform reach for a language of its lineage and era.

Why It Matters

Hot Soup Processor matters as a case study in accessibility-driven language design and in the regional, community-rooted software cultures that mainstream programming history often overlooks. It belongs to the same family of “make something fun appear on screen quickly” tools that have introduced countless people to programming — but it is distinctly Japanese in its origins and its strongest community.

Its longevity is its most striking trait. Born in the mid-1990s as a small freeware utility, HSP survived the transition to a modern open-source toolchain, picked up cross-platform runtimes for mobile and the web, and is still shipping releases nearly thirty years later. For the hobbyists and students it was built for — people who want the shortest possible path from idea to running program — HSP has quietly remained exactly what it set out to be.