-When running the PHP frontend:
- * [PHP](https://php.net) (7.3+)
- * PHP-pgsql
- * PHP-intl (bundled with PHP)
+These will be installed automatically when using pip installation.
+
+When using legacy CMake-based installation:
+
+ * [cmake](https://cmake.org/)
+ * [expat](https://libexpat.github.io/)
+ * [proj](https://proj.org/)
+ * [bzip2](http://www.bzip.org/)
+ * [zlib](https://www.zlib.net/)
+ * [ICU](http://site.icu-project.org/)
+ * [nlohmann/json](https://json.nlohmann.me/)
+ * [Boost libraries](https://www.boost.org/), including system and file system
+ * PostgreSQL client libraries
+ * a recent C++ compiler (gcc 5+ or Clang 3.8+)