Yes that is completely correct. OpenVPN implements... OpenVPNOpenVPN needs to be installed on clients. Protocols like IPSec, IKE, PPTP, or L2TP are not supported: http://wiki.blue-pan....2_OpenVPN_(en)
Unfortunately it does not support PPTP protocol.
Open VPN Iranians do not think we will.
Openvpn is much easier to configure, I've had lots less troubles with it then using IPsec (ike is a part of ipsec).
The question is (indeed) what do you need on "the other" side. I know there are ip-proxy services that accept openvpn connections. I think that's your best shot at the moment.
IPsec, on the other hand, needs support in the linux kernel (not there in the OpenPLi kernel), is a HELL to configure using linux and if you need to use IKE (which is very probably), I am very sure will quit long before you have it running.
L2TP depends on ipsec (in practise), PPTP could be doable, again if kernel support would be there in our kernel.