PostgreSQL is an open source relational database management system (RDBMS) developed by a worldwide team of volunteers.
PostgreSQL is not controlled by any corporation or other private entity and the source code is available free of charge.
In general, any modern Unix-compatible platform should be able to run PostgreSQL.
PostgreSQL also runs natively on Microsoft Windows NT-based operating systems like Windows XP, Vista, 7, 8, 2003, 2008, etc.
As this technology is not controlled by any specific organization hence there is no common standard certification for postgresql . There are some certification exams conducted by third party organizations.
Yes, Replication is supported by Postgre SQL like any other RDBMS.
Yes, It supports PITR as well.
PG_basebackup, PG_dump and PG_dumpall are the tools used for Backup and PG_restore is used for Recovery.
There are many, but PGAdmin III is mostly used and we also use it in our course.