The following response borrows shamelessly from Mr.Wizard:

Manipulate[ Graphics[{{Dashed, If[circle, Circle[{0, 0}, r], {}]}, Rotate[MapThread[ Rotate[Text[Style[#, FontFamily -> "Courier", fs], #2], 90 \[Degree] - #3] &, {txt, {-r Cos[#], r Sin[#]} & /@ (range = Range[0, arc, arc/(Length@txt - 1)]), range}], \[Theta], {0, 0}]}, ContentSelectable -> True, PlotRange -> 3, PlotRangePadding -> .5, ImageSize -> {500, 400}, Axes -> axes], {{fs, 20, "font size"}, 5, 50, Appearance -> "Labeled"}, {{r, 2, "radius"}, 0.1, 3, Appearance -> "Labeled"}, {{arc, 2.5, "arc length"}, 0, 2 Pi, Appearance -> "Labeled"}, {{\[Theta], 0, "location on arc"}, 0, 2 Pi}, {{circle, True}, {True, False}}, {{axes, True}, {True, False}}, Initialization :>   {txt = "This is some text to wrap" // Characters;}] 

Note: "Arc length" is based on the unit circle. 2 Pi, or approximately 6.28 corresponds to a 360 degree arc on the unit circle. The actual full arc length will be 2Pi*r.

The following response borrows shamelessly from Mr.Wizard:

Manipulate[ Graphics[{{Dashed, If[circle, Circle[{0, 0}, r], {}]}, Rotate[MapThread[ Rotate[Text[Style[#, FontFamily -> "Courier", fs], #2], 90° - #3] &, {txt, {-r Cos[#], r Sin[#]} & /@ (range = Range[0, arc, arc/(Length@txt - 1)]), range}], θ, {0, 0}]}, ContentSelectable -> True, PlotRange -> 3, PlotRangePadding -> .5, ImageSize -> {500, 400}, Axes -> axes], {{fs, 20, "font size"}, 5, 50, Appearance -> "Labeled"}, {{r, 2, "radius"}, 0.1, 3, Appearance -> "Labeled"}, {{arc, 2.5, "arc length"}, 0, 2 π, Appearance -> "Labeled"},   {{θ, 0, "location on arc"}, 0, 2 π},   {{circle, True}, {True, False}},   {{axes, True}, {True, False}},   Initialization :> {txt = "This is some text to wrap" // Characters;}  ] 

Note: "Arc length" is based on the unit circle. $2 \pi$, or approximately 6.28 corresponds to a $360^\circ$ arc on the unit circle. The actual full arc length will be $2\pi r$.

The following response borrows shamelessly from Mr.Wizard:

Manipulate[ Graphics[{{Dashed, If[circle, Circle[{0, 0}, r], {}]}, Rotate[MapThread[ Rotate[Text[Style[#, FontFamily -> "Courier", fs], #2], 90 \[Degree] - #3] &, {txt, {-r Cos[#], r Sin[#]} & /@ (range = Range[0, arc, arc/(Length@txt - 1)]), range}], \[Theta], {0, 0}]}, ContentSelectable -> True, PlotRange -> 3, PlotRangePadding -> .5, ImageSize -> {500, 400}, Axes -> axes], {{fs, 20, "font size"}, 5, 50, Appearance -> "Labeled"}, {{r, 2, "radius"}, 0.1, 3, Appearance -> "Labeled"}, {{arc, 2.5, "arc length"}, 0, 2 Pi, Appearance -> "Labeled"}, {{\[Theta], 0, "location on arc"}, 0, 2 Pi}, {{circle, True}, {True, False}}, {{axes, True}, {True, False}}, Initialization :> {txt = "This is some text to wrap" // Characters;}] 

The following response borrows shamelessly from Mr.Wizard:

Manipulate[ Graphics[{{Dashed, If[circle, Circle[{0, 0}, r], {}]}, Rotate[MapThread[ Rotate[Text[Style[#, FontFamily -> "Courier", fs], #2], 90 \[Degree] - #3] &, {txt, {-r Cos[#], r Sin[#]} & /@ (range = Range[0, arc, arc/(Length@txt - 1)]), range}], \[Theta], {0, 0}]}, ContentSelectable -> True, PlotRange -> 3, PlotRangePadding -> .5, ImageSize -> {500, 400}, Axes -> axes], {{fs, 20, "font size"}, 5, 50, Appearance -> "Labeled"}, {{r, 2, "radius"}, 0.1, 3, Appearance -> "Labeled"}, {{arc, 2.5, "arc length"}, 0, 2 Pi, Appearance -> "Labeled"}, {{\[Theta], 0, "location on arc"}, 0, 2 Pi}, {{circle, True}, {True, False}}, {{axes, True}, {True, False}}, Initialization :> {txt = "This is some text to wrap" // Characters;}] 

Note: "Arc length" is based on the unit circle. 2 Pi, or approximately 6.28 corresponds to a 360 degree arc on the unit circle. The actual full arc length will be 2Pi*r.