v class="demo-container">
      <textarea id="editor" spellcheck="false">
\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{graphicx}

\title{pdftex.js}
\author{Compile \TeX{} directly in your browser!}
\date{\today}
\begin{document}
  \maketitle

  \begin{align}
    E_0 &= mc^2    \\
    E &= \frac{mc^2}{\sqrt{1-\frac{v^2}{c^2}}}
  \end{align}
\end{document}
      </textarea>
      <pre id="log"></pre>
    </div>
    <script>
      /* globals pdftex */
      pdftex.setPdftexDir('./')
      if 