Greeting from the Representative: Fumihiro Matsui

Nice to meet you — I'm Fumihiro Matsui (���䕶�G), founder of RINEARN.
This page offers a brief introduction to RINEARN and to me.

Welcome — About RINEARN

Thank you for visiting the RINEARN website. RINEARN is a software development studio I operate independently as a sole proprietorship. Allow me to provide a brief introduction, including some background about myself and the journey of RINEARN so far.

About RINEARN, its software, and its activities

Perhaps - more likely than not - you have come across this site after using one of the freeware tools developed and published by RINEARN. In fact, this website originally started as a "repository" for distributing such creations during my student years, about 20 years ago. » History

At that time, I was majoring in physics at university, frequently engaging in numerical calculations and data analysis. As a programming enthusiast, I genuinely enjoyed these tasks. Over time, I began creating my own analysis software, and since I had gone through the trouble of developing them, I decided to share them publicly.

To make the website more lively, I also started uploading simple programs and sample code for calculations and visualizations, almost like writing blog posts.

Initially, this site was just a personal homepage for showcasing my hobby creations. However, some of these creations seemed to fulfill niche demands. Unexpectedly, they found use in various contexts, and I received feedback from users. These interactions led to surprising connections and exchanges, which turned out to be quite enjoyable. Before I knew it, I had been maintaining the site for over a decade.

Transitioning into a Sole Proprietorship Studio - Present Day

By then, I was no longer a student and had started writing programs professionally. At one point, I decided to establish a sole proprietorship studio. Over the years, this site and my creative activities had grown to hold a special significance for me, so I formally adopted the site name 'RINEARN' as the business name. This marked the official beginning of RINEARN as a software development studio in 2018.

Even after transitioning to a business, I continue to develop and release the analytical freeware tools and various programs that RINEARN originally focused on, treating them as part of my contribution efforts. I hope to keep these activities going as much as possible. This is because I, too, have relied on many free analysis/calculation software tools, libraries, and sample code from my student days to the present. Continuing these efforts is my way of giving back, albeit in a small way, and I hope they can be of use to others.

About Our Services (Business Activities) and Skills

As mentioned earlier, RINEARN currently operates as a development studio and freelance engineer, accepting work requests primarily in Japan. While the primary focus is on development and analytical tasks, as shown in the examples below, I can generally handle a wide range of requests within the scope of my capabilities.

Business Activities

Here are examples of the types of work I undertake.

Software Development

I accept requests for the development of new software, or for subcontracted tasks involving partial development of other developers' software projects.

Various Work Assistance and Support

I provide support or take on delegated tasks to assist with other company's operational activities. (Think of it as a "helping hand" service.)

Customization and Support for Existing Software

As part of the above services, I also handle modifications or extensions to existing code upon request, if possible. Additionally, I provide support for introducing software into specialized use cases, as well as related development tasks.

Qualifications and Skills

Doctor of Science (Physics), Ritsumeikan University, Japan, 2016

I previously conducted simulation-driven research in the field of quantum chaos. In particular, I studied the relationship between the degree of entanglement across multiple quantum systems and the duration of the systems' "quasi-irreversible" phenomena.
» Details of my research (doctoral thesis, Japanese)
   

For data analysis, I heavily used in-house software and simulators — including RINEARN Graph 3D. Being able to build and modify the tooling and infrastructure as needed was a real advantage. As a side effect, the public releases of our software also got better, which created a nice feedback loop.

Applied Information Technology Engineer, 2018

I passed Japan's Applied Information Technology Engineer Examination (AP) in 2018. My chosen subject areas were: Information Security, Programming, System Architecture, Embedded Systems Development, and Information Systems Development.

(I'd like to pick up one of the advanced-level certifications next, but... finding the time is hard!)

Supported Programming Languages (in order of usage frequency)

Java, C/C++, Python, JavaScript/TypeScript, C#, VB.NET, PHP, Fortran — and lately I've been dabbling in Rust.

I can, of course, work with our in-house languages VCSSL and Vnano. I rarely use them in client projects, but since I design and implement languages/runtimes myself, I'm comfortable picking up unfamiliar or niche languages as needed. Open to discussion.)

Layers

I mainly live on the software side. I do handle hardware-adjacent work when necessary, but it's a bit of an away game for me — more dog-paddle than dolphin.

Examples of Services Provided

Design-to-implementation of application software; feature extensions and maintenance; rendering/visualization/GUI work; a variety of data analyses; and other tasks as needed..

Announcements & Contact

Below are RINEARN announcements and ways to get in touch. Please feel free to reach out anytime.

RINEARN Announcements Page

A hub where we post release/update notes for each product and updates to this site.

Email & Web Form

On the page linked above, you�fll find a web contact form. We also list our email address — sending a direct email (instead of the form) is perfectly fine.

We also take questions on X (formerly Twitter)

Our announcements account (linked above) is open for questions, too. If you have quick how-to questions about using our software, feel free to ask there.

Front Desk AI

An AI that provides general guidance for RINEARN. It can also route your question to the product-specific AI assistants based on what you ask. It's still experimental — accuracy may vary — but please give it a try!