N.V Rosvall's homepage

Niko Rosvall

Updated: 2023-09-18

This is not much of a webpage when it comes to the design. I'm not a web designer, and I prefer web pages that are fast and simple. However, these pages should work OK on your preferred tracking device too.

For my blog, see my weblog.

The easiest way to contact me is by email: niko@byteptr.com. Or message me on Discord and if you're into long distance walking, welcome to my Discord server.

I like to turn off my computer and spend time in nature. However, I also write software:


I've written a lot of software during the years, but here are the ones I care about the most. These are in active development.


Bren is a bulk file rename tool for the shell. With Bren it's easy to rename multiple files (even hundreds of them) in one go. Bren also supports post-rename scripting using GNU Guile programming language, but you do not need to use it, in order to rename files.

Bren has it's own website in here.


Memo is a Unix-style note-taking software for POSIX compatible systems. At the moment it's tested on GNU/Linux and on FreeBSD, but it should be portable to other platforms. Memo also works on Cygwin and WSL. Memo runs in the Unix heartland, the shell.

Memo has it's own website in here.


SECRET is a cross platform, command line, file encryption program. It allows secure file and directory encryption from the command line. SECRET also includes SecretEngine.dll library which is an easy to use file encryption library for .NET.

SECRET is licensed under the MIT open source license. Source code is available on Github.

Download version 1.6 precompiled binary for Windows or for Linux and see SECRET manual (pdf) for usage. It also explains technical details about the encryption algorithms in SECRET.

SECRET is also available from FOSSHUB.

Both binaries for Windows and for Linux are standalone builds they do not need .NET to run.

Software not maintained anymore

If you would like to take over any of these projects, feel free to contact me, I'm happy to help.


Ylva is a command line password manager. Ylva is written in C and is licensed under the MIT license. Ylva is mostly developed on Linux, but should work on BSD too.



Wilhelmina is a password manager. It's an open source (licensed under GPLv3+) software. Source code is available on Github. It's written for Windows, but should be fairly portable to other operating systems.

Wilhelmina has it's own website in here.

Ancient things

Back in 2006 I was designing LTSP (Linux Terminal Server Project) for a classroom in Finland. Here's the design documentation (PDF, in Finnish).

I also created my own Linux Live-CD, back when they were not that common. See the documentation (PDF, in Finnish).

Copyright © 2023 Niko Rosvall