This is the sequel to my work on Fighters (see sig line for link), since I consider these two to be among the weakest of the core classes. Furthermore, they are completely outshined by Tome of Battle adepts. For monks, the problem is largely about combat, while as for Fighters, they needed more skills and out of combat options, on top of more combat versatility. Here are the changes I am considering to add, first of all:

Class disciplines: DW, DM, SD, SH, SS, TC. For the purposes of the Martial Stance class feature (below), and any feats or maneuver items the monk may choose, his monk level adds fully to his Initiator Level (IL) for these disciplines.
Martial Stance: At level 3, a Monk gains access to a single stance of his choice. The stance can be chosen from any of the nine disciplines, though he may only add his full Monk level to his Initiator Level for class disciplines, which limits his options for stances from other disciplines. Additionally, when selecting a new stance with this class feature, a Monk can choose to ignore all maneuvers known prerequisites. When doing so, treat his full IL as half what it would normally be (unlike most D&D math, this will cut a monks IL in non-class disciplines to his level) to determine the highest level stance he can qualify for. A monk who actually trains extensively in a discipline is capable of attaining greater mastery of stances than one who does not. This class feature is also gained at levels 5, 10, 14, and 18. Also, at each of these levels, a monk gains the ability once/day to change, activate, or deactivate his stance as an immediate action, rather than a swift action. Thus, a level 10 monk can use an immediate action to change his stance 3 times per day, for example.

Wholeness of Body: This class feature is being improved, to heal Monk level x Wisdom modifier hit points per day, unless Monk level x 2 would be higher. At level 15, a Monk may use this class feature as an immediate action. If used in such a way, it can heal damage as it occurs and prevent death, similar to the Close Wounds spell.

Rushing Torrent: At level 7, a monk has perfected his flurrying technique and can now add his additional flurry of blows attacks to any attack action, instead of being limited to a full attack action. This includes, but is not limited to, readied actions, charges, martial strike maneuvers, and Spring Attacks. The monk simply chooses to apply the flurry attacks at the start of the action (taking the appropriate attack penalty, if there is one). If the Monk has multiple attacks of opportunity allowed per round (such as from the Combat Reflexes feat), a monk may expend additional attacks of opportunity equal to the flurry attacks he wishes to add to a provoked attack of opportunity, delivering all of the attacks for just one provocation.

Just as the Fighter gained several maneuvers and great flexibility in selection of them, so too does the monk gain stances. While Fighter gained a maneuvers readied mechanic identical to the Warblade's (but keeping non-readied maneuvers as available once/encounter on top of it) and the ability to learn a great many maneuvers overall, Monk gets the option to change stances as an immediate action a few times/day. He also can completely ignore maneuver pre-reqs, which is somewhat necessary to actually learn some higher level stances w/o additional feat expenditure. Of course, he can never get to level 8+ stances if he needs to fall back on that option.

Rushing Torrent I consider essential to marry the monk's fast movement major feature to his flurry of blows. It also adds a great deal of offensive punch (haha!) for someone who actually sticks it out in monk. A frequent concern is that monks cannot keep up with other classes for damage. Idea came from my friend and the Snap Kick feat.

Wholeness of Body just seemed like it could use a boost to be useful, I see no harm in making it equal the healing capacity of Paladin's lay on hands. The level 15 benefit isn't enough to entice people to stay monk straight classed on its own, but hopefully will help.

I'm wondering if I should drop a class discipline. Six looks like too much. then again, Swordsage and my Gladiator Fighter both get 6. If I dropped one, it'd probably be Desert Wind.

I wanted to start on this, because when I do DM next time, I have very specific game world plans. I want low powered and low magic, with full casting classes required to multiclass every other level to keep their power down. I feel like the adept base classes would stand out as too strong in such a world, I'd like to try it with ToB the book allowed, but the classes banned. Therefore, Fighter and Monk would be the de-facto best ways to get some nine swords abilities with.