function(vcpkg_find_acquire_program VAR)
  if(${VAR} AND NOT ${VAR} MATCHES "-NOTFOUND")
    return()
  endif()

  unset(NOEXTRACT)

  if(VAR MATCHES "PERL")
    set(PROGNAME perl)
    set(PATHS ${DOWNLOADS}/tools/perl/perl/bin)
    set(URL "http://strawberryperl.com/download/5.20.2.1/strawberry-perl-5.20.2.1-64bit-portable.zip")
    set(ARCHIVE "strawberry-perl-5.20.2.1-64bit-portable.zip")
    set(HASH 6e14e5580e52da5d35f29b67a52ef9db0e021af1575b4bbd84ebdbf18580522287890bdc21c0d21ddc1b2529d888f8e159dcaa017a3ff06d8fd23d16901bcc8b)
  elseif(VAR MATCHES "NASM")
    set(PROGNAME nasm)
    set(PATHS ${DOWNLOADS}/tools/nasm/nasm-2.11.08)
    set(URL "http://www.nasm.us/pub/nasm/releasebuilds/2.11.08/win32/nasm-2.11.08-win32.zip")
    set(ARCHIVE "nasm-2.11.08-win32.zip")
    set(HASH cd80b540530d3995d15dc636e97673f1d34f471baadf1dac993165232c61efefe7f8ec10625f8f718fc89f0dd3dcb6a4595e0cf40c5fd7cbac1b71672b644d2d)
  elseif(VAR MATCHES "YASM")
    set(PROGNAME yasm)
    set(PATHS ${DOWNLOADS}/tools/yasm)
    set(URL "http://www.tortall.net/projects/yasm/releases/yasm-1.3.0-win32.exe")
    set(ARCHIVE "yasm.exe")
    set(NOEXTRACT ON)
    set(HASH 850b26be5bbbdaeaf45ac39dd27f69f1a85e600c35afbd16b9f621396b3c7a19863ea3ff316b025b578fce0a8280eef2203306a2b3e46ee1389abb65313fb720)
  else()
    message(FATAL "unknown tool ${VAR} -- unable to acquire.")
  endif()

  find_program(${VAR} ${PROGNAME} PATHS ${PATHS})
  if(${VAR} MATCHES "-NOTFOUND")
    file(DOWNLOAD ${URL} ${DOWNLOADS}/${ARCHIVE}
      EXPECTED_HASH SHA512=${HASH}
      SHOW_PROGRESS
    )
    file(MAKE_DIRECTORY ${DOWNLOADS}/tools/${PROGNAME})
    if(DEFINED NOEXTRACT)
      file(COPY ${DOWNLOADS}/${ARCHIVE} DESTINATION ${DOWNLOADS}/tools/${PROGNAME})
    else()
      execute_process(
        COMMAND ${CMAKE_COMMAND} -E tar xzf ${DOWNLOADS}/${ARCHIVE}
        WORKING_DIRECTORY ${DOWNLOADS}/tools/${PROGNAME}
      )
    endif()

    find_program(${VAR} ${PROGNAME} PATHS ${PATHS})
  endif()

  set(${VAR} ${${VAR}} PARENT_SCOPE)
endfunction()