Since this third party software released under different licenses than IPOPT, we cannot distribute that code together with the IPOPT packages and have to ask you to go through the hassle of obtaining it yourself (even though we tried to make it as easy for you as we could). Keep in mind that it is still your responsibility to ensure that your downloading and usage if the third party components conforms with their licenses.
Note that you only need to obtain the ASL if you intend to use IPOPT from AMPL. It is not required if you want to specify your optimization problem in a programming language (C++, C, or Fortran). Also, currently, Lapack is only required if you intend to use the quasi-Newton options implemented in IPOPT.