Dear, Taco and Hans Thanks for your answer. TeX-e-Parsi is better than omega because it was written a long time ago (15 years ago) and since then, the developer (Yazdipur) has modified and corrected the code. So firstly I think it does not have any bugs or if it has, it has a very small number of bugs comparing to Omega. Secondly TeX-e-Parsi have been used by the Iranians for the whole period and still people continue to use it and they are very happy with it since it is not buggy at all. I believe TeX-e-Parsi is much more advanced than Omega and it defines a set of new primitives to support LTR and RTL typesetting fully in addition to changing some of TeX codes. It also provides the \eqprimitive primitive so that we can define TeX primitive commands to the appropriate Persian/Arabic names and that can be done for any other language. So a user who does not speak English, does not need to learn TeX's English primitive to write macros, he just can use his language version of the primitives and at the same time the original TeX commands will work. Let me tell you that unfortunately the manual is written in Persian and that does not say anything about the actual engine, it is just Parsi LaTeX user manual. If you intend to look at this seriously, I will be more than happy to translate the comments in the tex.ch to English (Since the comments are written in Persian and TeX-e-Parsi is 8 bit, you will see some strange characters when Persian comments are present) Just let me, if you need me to write the comments in English. Thanks I trust my family jewels only to Linux _________________________________________________________________ Time for change? Find your ideal job with SEEK. http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fninemsn%2Eseek%2Ecom%2Eau%2F%3Ftracking%3Dsk%3Atl%3Ask%3Anine%3A0%3Ahottag%3Achange&_t=757263783&_r=SEEK_tagline&_m=EXT