The whole So1um PDF collection, and their transcription in Markdown.
So1um is a solo Role Playing Game designed & written by Matt Jackson.
It's published under the terms of the CC-BY 4.0 License.
You can also download the PDFs.
You can access the Version Changelog.
Note about the "so1um 1.0"
The first version was erroneously tagged '1.0', but it was supposed to be tagged as '0.1'.