So let me try this again. I have sqldeveloper 126.96.36.199 which I downloaded from Oracle and extracted into my home directory.
I then followed these steps:
$ cd sqldeveloper
Oracle SQL Developer
Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
OpenJDK 64-Bit Server VM warning: ignoring option MaxPermSize=256M; support was removed in 8.0
LOAD TIME : 414
Do you get any of the above or simply the warning?