Build 99 can be downloaded from here:

Windows (32-bit): Rainlendar-2.8.b99-32bit.zip
Windows (64-bit): Rainlendar-2.8.b99-64bit.zip
Linux TAR (32-bit): Rainlendar-2.8.b99-i386.tar.bz2
Linux DEB (32-bit): rainlendar2-pro_2.8.b99-1_i386.deb
Linux TAR (64-bit): Rainlendar-2.8.b99-amd64.tar.bz2
Linux DEB (64-bit): rainlendar2-pro_2.8.b99-1_amd64.deb
Mac OS X (Intel): Rainlendar-2.8.b99.dmg

MD5SUMS-b99

This is beta version! It has not been tested.

Changes:
o The visual category can now be used to overwrite only the base appearance and the icons can come from the event's category.
o The alarm is now limited to 28 days before the event when saving events to Google Calendar.
o Added an advanced option to keep the editor open while the event is written to the calendar.
o Fixed crash bug when a recurring task was set to December and written to RTM.
o It is now possible to use a localized help file too.
o The skin menu was opened in incorrect location. Fixed.
o The initial value of the font scale is automatically reduced if the DPI settings on Windows are > 100.
o Added option for the Outlook calendar to read the birthdays from contacts.
o The todo dialog prevents setting the start time after the due time.
o Cancelling a task will automatically dismiss the alarm too if it has one.
o Password fields show the amount of stars equal to the password length.

How can I use a localized help file?

Rainlendar will try to open the localized help file automatically by adding the name of the language to the end of the file (e.g. "Rainlendar2-Spanish.htb"). If such file is not found from the program folder the English help is shown instead.

Rainy wrote:
Rainlendar will try to open the localized help file automatically by adding the name of the language to the end of the file (e.g. "Rainlendar2-Spanish.htb"). If such file is not found from the program folder the English help is shown instead.
Ok, but now there isn't any help file localized, no?

There is a Spanish version but its htb file is not yet publicly available.