Q:

Penetration testing methodologies

There are several methodologies for penetration testing like OSSTMM, NIST and other frameworks.  What are the differences among them?  Who is the intended audience and where is the intended place/sector for these methodologies?  
I read their documentations, but could not decide. 

A:

The PTES -- http://www.pentest-standard.org -- has one aspect the other frameworks do not, actionability from tools -- http://www.nothink.org/metasploit/documentation/metasploit_msf_analysis_ptes.pdf
An updated version of the tools to perform a PTES-based pen test, including the MSF analysis is available here -- https://github.com/trustedsec/ptf
OSSTMM does have a tool component, but only available from the expensive training.  SANS has developed similar criteria to establish testing frameworks through expensive training, but they do have a great GPWN mailing list that is open to the public. 
IMO, NIST Special Pubs do not cover pen testing per se, because even SP 800-115 doesn't take into account the complexities necessary to define or organize the best-practice thought around pen testing as performed by Veris Group, Silent Break Security, Mandiant, or similar outfits.  The PCI-DSS guidelines go a lot further than what NIST provides, but it is still a bit lackluster -- https://www.pcisecuritystandards.org/documents/Penetration_Testing_Guidance_March_2015.pdf
To answer your question directly, I would say that the pen testing standards you referenced are outdated, while PTES is the commonly-held 2016 worldwide standard.  There are also standards for the UK, namely CHECK, CREST and CBEST.