A simple way to define inline comments for LaTeX. Extend with your own colours (e.g. xcolor package) and use cases (e.g. todos)

comments.tex

\usepackage{tcolorbox}

\newcommand{\setCommenter}[3]{
    \expandafter\newcommand\csname #1\endcsname[1]{\textcolor{#3}{\tcbox[on line, boxsep=0pt, left=2pt, right=2pt, top=2pt, bottom=2pt, colback=#3!80!white, arc=4pt, colframe=white, fontupper=\color{white}]{#2} [##1]}}
}

% define your comments here
\setCommenter{alice}{Alice A.}{blue}
\setCommenter{bob}{Bob B.}{red}

% make inline comments by going \alice{my cool comment}
% import into your main.tex file with \input{comments.tex}