Verbatim environment to split long words over lines

You can iterate through the verb, adding a breakpoint after each character.

\documentclass{article}

\makeatletter
\let\old@sverb\@sverb
\def\@sverb#1{\old@sverb{#1}\zz}
\def\zz#1{#1\ifx\@undefined#1\else\penalty\z@\expandafter\zz\fi}
\makeatother

\begin{document}


\raggedright

\verb|lllllllllllllllllllllloooooooooooooooooonnnnnnnnnnnnnggggggg$$$$$$$$$$$$$$$$llllllllllllloooooooooooooooonnnnnnnnnnnnnnnngggggggg$$$$$$$|

\verb|`?<<---|

\verb|`?<<---ooooooooooooooooonnnnnnnnnnnnnggggggg$$$$$$$$$$$$$$$$llllllllllllloooooooooooooooonnnnnnnnnnnnnnnngggggggg$$$$$$$|

\end{document}

A solution with xparse:

\documentclass[draft]{article}
\usepackage{xparse}

\ExplSyntaxOn
\NewDocumentCommand{\splitverb}{v}
 {
  \group_begin:
  \use:c { verbatim@font }
  \seq_set_split:Nnn \l_tmpa_seq {} {#1}
  \seq_use:Nn \l_tmpa_seq { \hspace{0pt plus .2em}\penalty\c_zero\hspace{0pt plus -.2em} }
  \group_end:
 }
\ExplSyntaxOff

\begin{document}

Some text \splitverb|lllllllllllllllllllllloooooooooooooooooonnnnnnnnnnnnnggggggg$$$$$$$$$$$$$$$$llllllllllllloooooooooooooooonnnnnnnnnnnnnnnngggggggg$$$$$$$|

Let's see that ligatures are not formed: \splitverb|`?<<---|

\end{document}

The combination of \hspace and \penalty ensures you don't get overfull boxes.

You may want to add some glue with small flexibility instead.

\documentclass[draft]{article}
\usepackage{xparse}

\ExplSyntaxOn
\NewDocumentCommand{\splitverb}{v}
 {
  \group_begin:
  \use:c { verbatim@font }
  \seq_set_split:Nnn \l_tmpa_seq {} {#1}
  \seq_use:Nn \l_tmpa_seq { \hspace{0pt plus 0.1pt} }
  \group_end:
 }
\ExplSyntaxOff

\begin{document}

Some text \splitverb|lllllllllllllllllllllloooooooooooooooooonnnnnnnnnnnnnggggggg$$$$$$$$$$$$$$$$llllllllllllloooooooooooooooonnnnnnnnnnnnnnnngggggggg$$$$$$$|

Let's see that ligatures are not formed: \splitverb|`?<<---|

\end{document}