et of library functions that allow
  client programs to pass queries to the <span class="productname">PostgreSQL</span>
  backend server and to receive the results of these queries.
 </p><p>
  <span class="application">libpq</span> is also the underlying engine for several
  other <span class="productname">PostgreSQL</span> application interfaces, including
  those written for C++, Perl, Python, Tcl and <span class="application">ECPG</span>.
  So some aspects of <span class="application">libpq</span>'s beha