> I recently upgraded my macbook to MacOS 10.11.  The compilation of MIDAS failed after the upgrade, 
> complaining about  
> 
> gcc  -c -g -O2 -Wall <snip> src/mongoose.c
> src/mongoose.c:322:10: fatal error: 'openssl/ssl.h' file not found
> 
> It seems that MacOS has now fully removed openssl header files (they were deprecated for a while).  There 
> seems to be some notes on that here
> 
> http://lists.apple.com/archives/macnetworkprog/2015/Jun/msg00025.html
> 
> Konstantin suggested installing open-source builds of openssl using MacPorts.  I did that and MIDAS 
> compiled fine.  I documented the procedure here:
> 
> https://midas.triumf.ca/MidasWiki/index.php/Installation/Compilation_problems#MacOS_10.11_.28El_Capitan.2
> 9_openssl_errors

The MIDAS Wiki page points to https://guide.macports.org/  which covers OSX up to 10.9. Installers for 10.10 and the current 10.11 
(El Captain) can be found here: https://www.macports.org/install.php

Stefan