IGZ Format

[Neo_Kesha]

Int32 - ASCII Signature
Int32 - Version (?)
Int32 - ID (?)
Int32 - six (wtf)
Few times chunk info, until offset is zero:

chunk info

Int32 - Usefull magic
Int32 - MAGIC
Int32 - offset
Int32 - size

...
Offset 0x220: some text, maybe memory pools
...
First chunk: meta info. Contains records.

record

Int32 - Type
Int32 - Items count
Int32 - size of whole record (data + header size)
Int32 - size of header
[spoiler=types]
Pair string : TDEP
String array : TSTR, TMET
Int32 array : MTSZ, ROOT (?), ONAM (?)
Pair Int32 array : EXID, EXNM
Something horrible: RVTB, RSTT, ROFS, RPID,REXT, RHND, RNEX
[spoiler=Pair string]
Items count times pair of null terminated strings
aligment to 4 (minimum one byte, never zero if already aligned)

String array

Items count times of null terminated strings aligned to 2
aligment to 4 (minimum one byte, never zero if already aligned)

Something horrible

Array of byte values

Second chunk:
16 zeros
Int32 count
Int32 count
Int32 length
Int32 MAGIC
Int32 table_offset
Int32 zero
count times Int32 offset and Int32 zero (of 64 bit offset? Nah)
Content
Int32 count
Int32 count
Int32 length
Int32 MAGIC
Int32 table_offset
Int32 zero
count times Int64 number Int64 number
Unexplored yet
Third chunk: data carried by IGZ?