For those folks on windows who want to do http gets and posts directly from your PostgreSQL server, we've made binaries for the http extension for PostgreSQL Windows.
These should work fine on both PostgreSQL EDB windows distributions as well as the BigSQL windows 64 distributions.
Instructions in the ReadMe.txt for where to copy the files to for each distribution. Caution should be taken especially with BigSQL to not overwrite existing BigSQL files.
Many of the files in this already exist in the BigSQL distribution since we both compile using the Mingw64 chain.
If you have PostGIS already installed, many of these files you will also already have since things like the libcurl and PCRE are also packaged with PostGIS.
We recently installed PostgreSQL 11 on an Ubuntu 18.04 using apt.postgresql.org. Many of our favorite extensions were already available via apt (postgis, ogr_fdw to name a few), but it didn't have the http extension we use a lot. The http extension is pretty handy for querying things like Salesforce and other web api based systems. We'll outline the basic compile and install steps. While it's specific to the http extension, the process is similar for any other extension you may need to compile.