Safari 5 tabs on Safari 6+. Cosy.

Tested on Safari 6, 7, 8, 9, 10.

Safari 10 was tested under macOS Sierra only.

If you're using an old version of Safari/macOS and you're having problems with the latest version, try the older ones.

Preview

How to Install

macOS Sierra (10.12)

Disable System Integrity Protection, and install the latest version of mySIMBL.

After that, download cosyTabs, extract it, and place cosyTabs.bundle in /Library/Application Support/SIMBL/Plugins/

Run Safari!

(Feel free to turn SIP back on after this installation, SIMBL will continue to work.)

El Capitan (OS X 10.11)

EasySIMBL does not work anymore because of the System Integrity Protection introduced in El Capitan.

It has been confirmed that the old SIMBL-0.9.9 works, but only after disabling SIP.

Here's the guide for installing SIMBL on El Capitan: https://github.com/norio-nomura/EasySIMBL/issues/26#issuecomment-117028426

After that, download cosyTabs, extract it, and place cosyTabs.bundle in /Library/Application Support/SIMBL/Plugins/

For advanced users

Obviously, there is no need to disable SIP (and reboot 4+ times). If you can extract SIMBL from the .pkg, boot into Recovery or any other OS, then you can simply copy the SIMBL's files to the correct paths.

OS X 10.10.4+ (Updated Yosemite)

1. Download and install SIMBL-0.9.9
2. Download cosyTabs here: Releases
3. Extract it, and place cosyTabs.bundle in /Library/Application Support/SIMBL/Plugins/

OS X 10.7 → 10.10.3

1. Download and install EasySIMBL
2. Download cosyTabs here: Releases
3. Extract & Install cosyTabs:
   • Open EasySIMBL and drag & drop cosyTabs.bundle into the list.

Note about Safari Technology Preview

I could not get SIMBL to inject into Safari Technology Preview (STP), so STP is unsupported at the moment.

Please create an issue if you have a clue on how to fix this error:

Safari Technology Preview[3466:43691] Error loading /System/Library/ScriptingAdditions/SIMBL.osax/Contents/MacOS/SIMBL:  dlopen(/System/Library/ScriptingAdditions/SIMBL.osax/Contents/MacOS/SIMBL, 262): no suitable image found.  Did find:
	/System/Library/ScriptingAdditions/SIMBL.osax/Contents/MacOS/SIMBL: mmap() error 1 at address=0x10AF27000, size=0x00004000 segment=__TEXT in Segment::map() mapping /System/Library/ScriptingAdditions/SIMBL.osax/Contents/MacOS/SIMBL
Safari Technology Preview: OpenScripting.framework - can't find entry point InjectEventHandler in scripting addition /System/Library/ScriptingAdditions/SIMBL.osax.

License

This program is licensed under GNU GPL v3.0 (see LICENSE)