It’s originally written by Paul Dunn and currently maintained by Arda (“Ref”).
This is the only official page for Basin & it’s current fork, Basinc. Basin is discontinued and unsupported after version R14c. While development versions of R15.8 is available around internet but it’s never completed. While migrating to code to a new environment it got a bit messy and Paul stopped working on it and send the latest source code to me. The code couldn’t be compiled, because it got too many errors to fix. Rather than trying to figure out how to get it to compile, I used R14 as a base, which is kind of stable build but it was very limited compared to R15, and I integrated and updated the new functions of R15 into R14 source code.
The result is a hybrid of both versions, and I started fixing bugs, adding features most requested. I wasn’t planning to release anything because I hoped Paul might return working on basin again, but as it’s working vigorously on SpecOS, I suspect this will not become true in near future. So I decided to release basin under different name, Basinc, just to distinguish it’s not an upgrade to R15.8, and it’s going to a different route, as a fork of basin. Right now, I am the only official maintainer of Basin and BasinC. Source code of both programs are available in their respective archives. I can answers question releated to Basin but I won’t be the man to update it.
You can download the v1.69 version here V1.69 (02.07.2014).
edit: Please check downloads section for a newer version (v1.7 is already out).
You may find all basinc releases in “sinclair zx spectrum > BASin/basinc category”