I figured out how to build the Russian version (sort of)

[pharpend]

Last I checked, y'all were having issues with TeX and the Cyrillic alphabet.

• First of all, don't import inputenc.
• Next, you need to install the Cyrillic alphabet pack for TeXLive. On Arch Linux, this package is texlive-langcyrillic.

Then run ./build and you'll be golden-ish. This may be an issue on my machine, but:

[pharpend]

I got this far with some limited success:

diff --git a/ru/build b/ru/build
index 3829971..3c9050f 100755
--- a/ru/build
+++ b/ru/build
@@ -18,9 +18,9 @@ mkdir tmp
 cp -rvf lysa.ltx appendices/* chapters/* bibliographies/* images/* tmp/
 cd tmp

-pdflatex lysa.ltx || clean_and_die 1
+xelatex lysa.ltx || clean_and_die 1
 bibtex lysa
-pdflatex lysa.ltx && pdflatex lysa.ltx
+xelatex lysa.ltx && xelatex lysa.ltx

 cp lysa.pdf ..
 clean_and_die 0
diff --git a/ru/lysa.ltx b/ru/lysa.ltx
index b6f6153..710c8af 100644
--- a/ru/lysa.ltx
+++ b/ru/lysa.ltx
@@ -23,9 +23,6 @@
 \usepackage[toc,page]{appendix}
 \usepackage[backend=bibtex]{biblatex}
 \usepackage{centernot}
-\usepackage[answerdelayed]{exercise}
-\usepackage[T1]{fontenc}
-\usepackage[utf8]{inputenc}
 \usepackage{listings}
 \usepackage{mathtools}
 \usepackage{relsize}
@@ -37,6 +34,11 @@
 \usepackage[hidelinks]{hyperref}
 \usepackage{cleveref}

+% Russian
+\usepackage[T2]{fontenc}
+\usepackage[utf8]{inputenc}
+\usepackage[russian]{babel}
+
 \crefname{chapter}{\S}{\S}
 \crefname{section}{\S}{\S}
 \crefname{subsection}{\S}{\S}
@@ -93,7 +95,7 @@
 \newcommand{\link}[2]{#2 (\url{#1})}

 % Section & Chapter he
-\newcommand{\ch}[1]{\chapter{#1}\label{ch: #1}}
+\renewcommand{\ch}[1]{\chapter{#1}\label{ch: #1}}
 \newcommand{\s}[1]{\section{#1}\label{s: #1}}
 \renewcommand{\ss}[1]{\subsection{#1}\label{ss: #1}}
 \newcommand{\sss}[1]{\subsubsection{#1}\label{sss: #1}}
@@ -186,15 +188,17 @@
 {
   \newpage
   \ss{Exercises}
-  \begin{ExerciseList}
+  \begin{enumerate}
 }
 {
-  \end{ExerciseList}
+  \end{enumerate}
   \newpage
   \sss{Answers}
-  \shipoutAnswer
   \newpage
 }
+\newcommand{\Exercise}{\item}
+\newcommand{\Answer}{\item}
+
 \newenvironment{iquote}{\begin{quote}\it}{\end{quote}}

 \lstnewenvironment{plainfile}[1][]
@@ -216,6 +220,7 @@

 \newcommand{\filepath}{\texttt}

+% \DeclareUnicodeCharacter{00A0}{ }

 \title{Learn You Some Algebras for Glorious Good!}
 \begin{document}

Here's the result:

This might help: https://tex.stackexchange.com/questions/816/cyrillic-in-latex

[gazay]

Great, thank you for help!

[pharpend]

It may be better for y'all to write the book from scratch (i.e. a fresh TeX document). That way, you can build in the Russian stuff from the start, instead of having to patch everything up.

Additionally, the format is not rigid. That is, you could make this into a website, EPub, what-have-you. You don't have to make it a PDF.